Bcl-2 gene expression in hematopoietic cell differentiation.

The expression of bcl-2 appears to be typical ofcertain lymphoid malignancies. High levels of bcl-2 mRNAhad been found, previously, in established pre-B-cell lines.However, in fresh specimens, the peak level of bcl-2 expressionshifts to a more differentiated cell type, represented bythe long-living B lymphocytes that are found in most cases ofchronic lymphocytic leukemia. bcl-2 gene product might havea role in prolonging cell survival and, even in the absence oftranslocations, might contribute to some of the biologicfeatures that are typical of this disorder.