Tak Wah Mak, (; born October 4, 1946, in China) is a Canadian medical researcher, geneticist, oncologist, and biochemist. He first became widely known for his discovery of the T-cell receptor in 1983 and pioneering work in the genetics of immunology. In 1995, Mak published a landmark paper on the discovery of the function of the immune checkpoint protein CTLA-4, thus opening the path for immunotherapy/checkpoint inhibitors as a means of cancer treatment. Mak is also the founder of Agios Pharmaceuticals, whose lead compound, IDHIFA®, was approved by the FDA for acute myeloid leukemia in August 2017, becoming the first drug specifically targeting cancer metabolism to be used for cancer treatment. He has worked in a variety of areas including biochemistry, immunology, and cancer genetics. Early life Born in southern China in 1946 to parents who were silk merchants, and raised in Hong Kong, parents encouraged him to become a doctor, his interests lay elsewhere - in math, biology, and chemistry. Mak and his family moved to the United States of America during the mid-1960s and with the choice of going to the University of California or Wisconsin, he was persuaded by his mother to attend Wisconsin to avoid the antiwar activities at California. His interest in life and chemistry led him to eventually studying biochemistry and biophysics at the University of Wisconsin. University life At the University of Wisconsin, Mak met virologist Roland Rueckert. Mak initially went to his lab to inquire about a job posting from Rueckert's lab looking for someone to wash test tubes. After his first day on the job, Mak asked if more cleaning work was available, in which Rueckert said there was not, however there was experimental research work available. That, as Mak would later state, would be the beginning of his scientific career. After finishing his degree at Wisconsin, Mak moved to Canada to begin his doctoral studies at the University of Alberta, Edmonton. In the early 1970s, he earned his PhD in biochemistry from the University of Alberta. After he obtained his degree, Mak moved to Toronto and became a Canadian citizen. In Toronto, he worked with Ernest McCulloch and James Till, who discovered haematopoietic stem cells. Scientific career In 1980, Mak returned to Wisconsin to learn new techniques in the lab of Howard Martin Temin, who won the Nobel Prize in Physiology or Medicine in 1975 for his discovery of the