Heavyweight Sherman Pendergarst lost his battle with cancer Friday at Genesis Medical Center in Davenport, Iowa, the fighter's longtime trainer and friend Pat Miletich told ESPN.com.
Pendergarst, 45, was not among the most-skilled mixed martial artists. But he was second to none when it came to being respected by his peers and fans.
"I really hate it when people (who) care for everyone are afflicted with suffering," Miletich said. "He was such a gentle soul."
Pendergarst last competed on Feb. 18 against Bruce Nelson. The light heavyweight bout was declared a no-contest when Pendergarst landed an illegal strike.
He fought once in UFC, losing by first-round knockout to heavyweight Antoni Hardonk in November 2006.
In his lone Bellator appearance on May 1, 2009, Pendergarst suffered a first-round TKO to Joey Beltran.
Pendergarst had a professional record of 11-18 with one no-contest.
Pendergarst was diagnosed with colon cancer more than a year ago, but he refused to retire despite repeated insistence from Miletich and others at Miletich Fighting Systems in Bettendorf, Iowa, to do so.
"I can confirm that he had cancer for his last fight," Miletich said. "I was (angry) when I found out that he had already fought.
"I stopped training him after learning that he had been diagnosed with cancer. I wanted him to quit fighting."
His final bout took place in Fargo, N.D., while he was being treated for cancer. Pendergarst failed to inform the North Dakota Commission for Combative Sports of his physical condition.
His prefight blood work did not reveal evidence of cancer.
"It was just HIV, Hepatitis B and C," commission representative Linda Gregoryk told ESPN.com of what it tested for. "And they all came back negative. That was all that was on that blood test. So there we wouldn't have known (about his cancer).
"On our medical form, we asked him several questions, there are 10 or so, and one of them is, 'Do you have a serious condition?' And, of course, everything he said was no, no. no. So we didn't catch anything there."
If Pendergarst had revealed his physical ailment he would not have been allowed to compete on the card.
"Certainly we would not have allowed him to fight," commission spokeswoman Mary Feist told ESPN.com in a statement. "And if he'd insisted that he was going to fight, he would have had to have passed a really strenuous doctor's test saying that a doctor would approve him to fight.
"No doctor that I know of would have allowed him to fight."
ESPN.com left a message with CFX owner Brock Larson, whom the commission has listed as the promoter of the Feb. 18 event. But no one from the promotion has responded.
"The one thing that was cool about Sherm is that he spent a lot of time helping the young guys," Miletich said. "He was always advising them, helping line them up with fights."