Ira Pastan (born in Winthrop, Massachusetts June 1, 1931) is an American scientist at the National Cancer Institute. He is a member of the National Academy of Sciences, a Fellow of the AAAS and the American Society of Microbiology. In 2009, he was awarded the prestigious International Antonio Feltrinelli Prize for Medicine. His wife, Linda Pastan, was an American poet. Biography Pastan attended the Boston Public Latin School, Tufts College, and Tufts Medical School. He did his residency at the Yale School of Medicine (1957-1959). Pastan conducted research training in endocrinology at NIH with Earl Stadtman starting in 1959. In 1970, he founded the Laboratory of Molecular Biology (LMB) in the National Cancer Institute (the largest Institute of the National Institutes of Health). He is currently co-chief of the LMB and is working on various Immunotoxin Therapies. Research activities Pastan pioneered the field of receptor biology in animal cells and identified a major receptor mediated pathway of gene regulation in bacteria. With Robert L. Perlman, he established the first general mechanism of positive gene regulation in bacteria showing that cyclic AMP and its receptor protein CRP (cyclic AMP receptor protein) positively regulated the activity of many genes. These studies serve as a paradigm for the mechanism of action of cyclic AMP and steroid hormones on gene expression in animal cells. His current research is focused on developing Recombinant Immunotoxins (RITs) as a new treatment for cancer. Gene splicing techniques are used to make chimeric proteins in which the Fv of an antibody, preferentially binding to a cancer cell, is attached to a potent bacterial toxin. Additionally, with his colleague Jesse Roth, he was the first to clearly demonstrate the presence of specific protein receptors on the surface of animal cells. To explain the biochemical basis of hyperthyroidism, Pastan showed that antibodies from the serum of patients with hyperthyroidism specifically activated thyroid gland adenylate cyclase, providing an immunological mechanism for hyperthyroidism. He then proceeded to study hormone interactions with living cells using fluorescence photo-bleaching to visualize polypeptide hormone-receptor complexes bound to the membrane of living cells. He showed these complexes were highly mobile and clustered before entry into cells, and measured their lateral diffusion coefficients. In collaboration with Mark Willingham, he developed and used video intensified microscopy to visualize fluorescently labeled insulin and EGF forming clusters on the surface of living cells prior to entry through the endocytic pathway. These studies