Peter Nowell

Peter Nowell co-discovered the Philadelphia chromosome in 1960 with David Hungerford, the first chromosomal abnormality identified in a human cancer, establishing the principle of genetic specificity in cancer. This discovery ultimately led to the identification of BCR-ABL fusion and the development of imatinib. Nowell's subsequent concept of clonal evolution of cancer — that tumors progress through sequential selection of increasingly malignant subclones — remains a cornerstone of cancer biology.