Nature Immunology 4, 1155–1157 (2003).

A description of C. Thompson's studies on B cell development in birds on page 1157, third full paragraph, should have read, “C. Thompson (University of Pennsylvania), like Cooper, has exploited the utility of immunological studies of various organisms and identified the mechanism of immunoglobulin diversification in the bursa of Fabricius (independently identified by C.A. Reynaud and J.-C. Weill) first noted by Cooper. Thompson described his work on the apoptotic control of lymphocyte development and differentiation.”