ABSTRACT
During the past two decades, evidence has accumulated indicating that tumor formation is often associated with the occurrence of nonrandom chromo somal abnormalities (1 ,2) . Hematopoietic neoplasms (see chapters by Rai mondi, and also Anastasi and Roulston in this volume) account for less than 1 0% of human cancers, but karyotypic data regarding leukemias and lym phomas predominate, with solid tumors representing only about I 5 % of the total available data (3) .
