In 1969 we reported an aggregation of chronic lymphocytic leukemia in three siblings, together with immune defects that may have contributed to the familial predisposition (1). This follow-up study extends the range of B-cell neoplasms and immune defects occurring in this family (Figure 1). In 1974, the 42-year-old daughter (III-2) of the proband developed stage III-A, nodular, poorly differentiated lymphocytic lymphoma, which responded to cyclophosphamide, vincristine, and prednisone. She relapsed in June 1978 and responded to a second course of the same drugs. As a child, numerous vaccinations were unsuccessful; but subsequently, she showed no unusual susceptibility to infection. The