GOP presidential candidate Fred Karger on Monday said he would remember his friend Mike Tidmus as a fighter and a tireless crusader for HIV/AIDS.

The 60-year-old Tidmus died on Sunday after losing a prolonged battle with cancer, LGBT POV, a blog of Frontiers LA, reported.

Tidmus' brother, Lindsay, simply posted on Facebook: “It is with a heavy heart that I inform his Facebook friends of Mike's passing. He left us this morning after a battle with cancer.”

The San Diego-based activist was “always front and center when it came to injustice against LGBT people,” Karen Ocamb wrote on LGBT POV.

Before working with Karger on his bid for the White House, Tidmus was involved in Karger's protests against major donors to California's anti-gay marriage initiative, Proposition 8.

“It's a sad time for the entire Lesbian, Gay, Bisexual and Transgender community,” Karger told On Top Magazine in an email. “Mike was a longtime activist on behalf of all of us. … He was a fighter right down to his final days.”

“Mike was a tireless crusader for HIV/AIDS for over two decades. He was open about being HIV positive and courageously fought the system to help with funding, awareness and care,” Karger added.