The worst pain a parent can feel is losing a child. The heartache never truly leaves; it just recedes into the background.
Steve Cunningham is a boxer, and a God-fearing man whose faith helped him endure a month at sea in the Persian Gulf while serving in the Navy. He's used to being hit in his midsection, but the gut shot he received while sitting next to his wife, Livvy, in a doctor's office was worse than any blow he's ever taken in a boxing match.
Just three days after beating Kelvin Davis, Cunningham was at his wife's side as she gave birth to their daughter, Kennedy.
Kennedy would be the couple's second child, following Steve Jr. When he flew home to Philadelphia from Cleveland after the win over Davis, all Cunningham could think of was Kennedy's impending arrival.
He couldn't wait to hold her in his arms, to caress her, to tell her how much he loved her.
It would be a painful meeting.
Kennedy Cunningham was born on September 6, 2005, with a congenital heart defect known as hypoplastic left heart syndrome that affects one in every 4,300 children born in the US each year. In simplest terms, the left side of the child's heart is undeveloped.
When Cunningham and Livvy had gone for an ultrasound months earlier to learn the gender of their second child, they'd learned the bad news.
A specialist ran them through the options, one of which included abortion. Neither Steve nor Livvy ever gave it a moment of thought.
"The specialist was explaining hypoplastic left heart syndrome and telling us what the situation was," Cunningham said. "She was telling us how they usually fixed it, what the treatment was, what the outlook might be, and at that time, she said we had the option to abort.
"That was shot down immediately. That would have been the easiest thing to do, but there was no way. No, no thanks. That wasn't happening."
The Cunninghams got to hold Kennedy for about 10 minutes after she was born. Soon, though, nurses came and took the baby away to undergo life-threatening surgery.
Steve Cunningham knew as he watched his daughter being taken to the operating room at the Children's Hospital of Philadelphia that he might never get to see her again.
He's an outgoing, ebullient type of guy, but one has to strain to hear him speak about Kennedy's early days.
Steve, Livvy and Steve Jr. were at the hospital every day for a year, hoping against hope that Kennedy would somehow survive and be able to go home with them.
"You should already appreciate what you have, but being together like that for as long as we were, that makes you appreciate what you have even more," he said. "Every day I got up, I knew it could be my last month, my last week, my last day, my last minutes with her. ... It just makes you love her more, fighting that fight with her, and you learn quickly what is really important in your life."
Some might say that on Saturday, when Steve Cunningham meets Tomasz Adamek in a nationally televised bout on NBC that is a rematch of one of 2008's best bouts, it will be the fight of his life.
A two-time cruiserweight champion, Cunningham has spent most of his career in the background. He was never promoted particularly well, and often was shunned in favour of others. He fought for relative peanuts and had to travel the globe to do it.
It wasn't the easiest way to get ahead in boxing, but Cunningham persevered.
If he beats Adamek, he'll need to win maybe one more fight to get a shot at the heavyweight title.
Adamek is a formidable foe who may be the world's best heavyweight not named Klitschko. It will be hard, and the odds are against him.
The outcome is important, and he makes no secret of that.
"A win would do so much for us and our family," says Livvy Cunningham, who serves as her husband's manager. "We get it."
It is not, though, the fight of his life. When you're dealing with a situation like he is with his young daughter, you gain perspective on things.
"You wonder why it happened to you and all that, but I believe that God put us in this situation because He knew we could handle it," Cunningham said.
That Cunningham is anonymous going into his first fight on national television in the US is startling. He is, after all, the kind of guy who would seem to be a promoter's dream.
He served in the Navy and spent time in the Persian Gulf, leading a crew that refuelled jets that were flying over Iraq.
He is a friendly and affable sort who was racking up an impressive record.
Yet, he still was brushed aside, put into low-visibility fights and not treated as a viable prospect.
He'd signed with Don King and felt that King would exploit his military background. He had delusions of grandeur that were quickly shattered.
"My wife says this about Don now, that when he first sees you, he puts dollar signs on you," Cunningham said. "He's going to spend his time promoting the guys where he sees the most dollar signs. With me, I'm not sure why, but he saw me and kind of forgot about me. I fought on undercards and it was like he wanted me to remain in obscurity.
"When I signed, it was not long after 9/11. That was a super patriotic time in this country. I thought they'd promote me that way, fly me to Afghanistan to talk to the troops, that kind of thing. I went to Poland and won a world title in the belly of the beast, so to speak. I'd been a top cruiserweight for a while, but it didn't really seem to matter to Don."
He's been a professional since 2000 and said that he only recently surpassed a million dollars in career earnings.
While there are boxers like Floyd Mayweather Jr. and Manny Pacquiao who make in excess of $50 million a year, there are plenty more like Cunningham who are making more like $50,000.
"I'm not saying I'm the lowest-paid two-time champion out there, but anybody who thinks that I'm rolling in money doesn't really know the truth or understand about boxing," he said. "It's OK. I'm not about money. I want to make money, obviously, so I can do for my kids, to give them the kind of life growing up I didn't have.
"Me and my wife, our thing is to give glory to God in what we do. As long as we have food on the table for our family and we're enjoying each other and what we're doing, at the end of the day, that's what counts."
The rematch with Adamek was a long time in coming. Cunningham went down three times in that fight and still only lost by split decision.
He thought it was a natural rematch and expected it to occur in short order. It didn't. Adamek moved to heavyweight and established himself as one of the elite in that division.
Cunningham reclaimed not only his cruiserweight belt after Adamek moved up, but he also reclaimed his position as perhaps boxing's most anonymous champion.
"The hardcore fans, the really, really diehard fans, those people knew about us and we've always appreciated their support," Livvy Cunningham says. "But the division itself, for whatever reason, isn't very popular in America. It's like if you fight at cruiserweight, you become invisible. We had to go fight overseas because that's where the money was, but nobody over here knew what we were doing."
The first fight wasn't widely seen, despite its brilliance. Cunningham felt he was doing what he needed to do to win, but he kept running into punches that would knock him down.
Losing three points via knockdowns makes a fight extraordinarily difficult to win. It was also frustrating to Cunningham because they were coming seemingly out of nowhere.
"I felt he wasn't more skilful than me," he said. "It was these shots that were catching me. It was mysterious. I was like, 'What's this dude got, bricks in his gloves?' I was doing my work and it kept happening."
The rematch, he vows, will be different. He's confident of a win and is excited by the fact that if he wins, he'll get to fight Kubrat Pulev to become the mandatory challenger for Wladimir Klitschko's belt.
That provides him plenty of motivation.
He doesn't need more, but whenever he returns home, however, he finds it.
Kennedy Cunningham is now 7, and her mother says she's "Just this beautiful, lively little girl who loves life, loves to have a good time who is walking around with half a heart."
Her prognosis is mixed. Three surgeries are required to fix hypoplastic left heart syndrome, and Kennedy has had two.
Doctors, though, aren't sure if she's physically up to the third surgery.
"We're kind of stuck in this unfortunate holding pattern," Livvy Cunningham said. "Her doctors really aren't sure what is next. To complete the repair on her heart, there is one more surgery that needs to be done. The problem is, this is such a crazy case and they're not sure she is a candidate for a third surgery.
"If she's not, then we're going to be looking at a heart transplant. ... We just don't know. So we're not sure what is next. We have to put things into perspective and just enjoy every day we have together. We're kind of a goofy family and we like to play and joke around and laugh with each other a lot. That's what we do to stay optimistic."
Life has dealt him a lot. He's been great at his job, but hasn't been accorded the kind of respect it seems he's earned. He hasn't made the money that others in similar, or lesser, situations have made.
His child, the daughter he so desperately wants and that he fights so hard to protect, lives a precarious life.
The Cunninghams live with an uncertainty, never knowing what the next day will bring.
Living through Kennedy's fight for life, though, makes it easier for Steve to accept the many slights he's been dealt in his boxing career.
"Look, everyone wants to be praised and recognised for what they do," he said. "That's human nature. But it's also really small in the grand scheme of things. I've got a beautiful little girl and she needs someone to fight for her and that is what is important. That's the thing that really matters.
"That other stuff, hey, I'd give everything up in a second to make Kennedy OK. When you live through something like we have with Kennedy, you learn what matters, what doesn't and what to let roll off your back and forget about."
The Adamek fight is a milestone for Cunningham, but it's not what is truly important. Win or lose, Kennedy Cunningham's struggle for survival is Steve Cunningham's most significant fight.