Introduction for Donald Metcalf
It is a personal pleasure to introduce my friend and former colleague, Donald Metcalf. He is best recognized as one of the founding fathers of modern experimental hematology, but we should not forget his pioneering work on the thymus. From 1956 and the decade thereafter, Don undertook a series of elegant studies on thymic cell kinetics and was one of the first to analyze the impact of thymectomy and thymic grafting on lymphopoiesis. Indeed, he should be considered the first to demonstrate the effects of thymectomy on lymphoid tissue and the autonomous control of lymphocyte proliferation within the thymus. In addition, his analysis of leukemogenesis in AKR mice is still considered definitive, revealing his ability to compare and contrast the cellular biology of the normal and neoplastic to gain insight into the etiology and pathogenesis of leukemia.