The "Berlin Patient" as he is known had HIV since 1995. He is a homosexual who was diligently on ARV medication for many years and kept to himself living a quiet and private life in Germany. Hence the alias.

In 2006/2007 he developed the most common blood cancer in adults called Leukemia.
Chemotherapy didn't help and his last chance was a stem-cell transplant from a bone marrow donor. So far, nothing is unusual in this line of treatment.
His oncologist who specialized in blood cancer Geto Hütter had a brain wave; he remembered that people with a natural genetic mutation called delta 32 disabled or stopped CCR5. This is a protein found on the very cells which is the pathway of HIV into human bodies.
If both parents have this CCR5 genetic mutation, early research showed that people with this mutation were immune to getting HIV. What was fascinating is that this genetic condition seems to occur only in Northern Europe which includes Germany.

Now this is the part that makes it interesting and unusual; his oncologist found a stem cell match with 232 donors but only one donor number 61 had both parents with this delta 32. THIS HAD NEVER BERN DONE BEFORE!

In February 2007, the "Berlin patient" had his stem cell transplant from Donor 61. This procedure is very invasive and kills a lot of patients. Luckily, after two attempts and a near death experience, the "Berlin Patient" survived.

After the treatment, not only was his leukemia in remission, his HIV levels were undetected and have remained so ever since.
His immune system was replaced with a brand 'new' immune system minus the cancer and the HIV and to this day remains the only person to be cured.

After his successful treatment, an attempt was made on 6 other HIV patients with cancer but unfortunately, all 6 died from the cancer or complications through the transplant.

The very elusive "Berlin Patient" finally accepted his new found fame and has started to do interviews and is reaching out to help others living with HIV. His name is Timothy Brown.

Read more here :
https://www.fredhutch.org/en/news/center-news/2015/02/aids-icon-timothy-ray-brown.html