Timothy Ray Brown, the first known person to be cured of HIV, has died of cancer. He was 54.

Known as “the Berlin patient,” Brown, who was born in the United States, was living in Berlin when he was diagnosed with HIV, the virus that causes AIDS, in 1995. In 2007, he developed acute myeloid leukemia, a type of blood cancer.

Brown's cancer treatment included a bone marrow transplant from a donor with a rare gene mutation, making the donor naturally resistant to HIV. This resistance was transferred to Brown.

Brown was considered cured of HIV in 2008, giving the world hope for a cure.

According to CNN, Brown had been living with a recurrence of leukemia for the last six months. It had entered his brain and spine.

In a Facebook post, Brown's partner Tim Hoeffgen called him his hero.

Brown “committed his life's work to telling his story about his HIV cure and became an ambassador of hope,” Hoeffgen wrote.

“I am truly blessed that we shared a life together but I'm heartbroken that my hero is now gone. Tim was truly the sweetest person in the world. Tim's spirit will live on and the love and support from family and friends will help me through this most difficult time.”

According to the Joint United Nations Programme on HIV/AIDS, there are 38 million people worldwide currently living with HIV or AIDS.

A second person effectively cured of HIV was known as “the London patient.” Adam Castillejo received a similar treatment given to Brown.