Anderson Cooper and Rosie Perez on Thursday remembered AIDS activist Spencer Cox.

Cox, who had been involved in AIDS-related activism for over 20 years, died Tuesday at the age of 44 in New York City of causes related to AIDS.

(Related: AIDS activist Spencer Cox dead at age 44.)

Cooper paid tribute to Cox during a segment on his daytime talk show with co-host Perez.

“You know, every now and then you come across real life heroes,” Cooper told his audience. “People who have done remarkable things particularly at a young age. And there was a man named Spencer Cox who died yesterday at the age of 44. He was an AIDS activist when he was like 20 years old. He was a spokesman for a group called ACT UP. He later went on to found a group called TAG, the Treatment Action Group. Which really revolutionized the way the medicine was tested and ultimately delivered to people. And he really helped speed up drug trials that got life-saving HIV medication to people. Saved countless lives by helping to speed up this process.”

Perez added that she was inspired by Cox's advocacy. (The video is embedded on this page. Visit our video library for more videos.)