Angelo John founded the A. P. John Institute for Cancer Research in 1978. In previous years, he worked in cancer research with C. Chester Stock, Ph.D., during the latter's tenure as Scientific Director at the Sloan-Kettering Institute for Cancer Research in New York City and Director of the Institute's Walker Laboratory in Rye, New York. He also operated his own research laboratory for more than 18 years. He spent 45 years researching, pioneering, and validating some of the most advanced clinically proven protocols for the treatment of cancer.