We have investigated the expression of oncogenes and other related genes in eleven patients with T-cell lymphoproliferative disorders and ten patients with other hematologic malignancies. The phenotypes of the T-cell disorders were determined using monoclonal antibodies specific for helper or suppressor subsets. RNA preparations were isolated from peripheral blood mononuclear cells and/or lymph node sections, 5'-end labeled with gamma-32P-ATP, and hybridized under stringent conditions to an excess of nitrocellulose-bound specific cloned DNA; autoradiographs were analysed by microdensitometry. Results revealed increased expression of K-ras, v-fps, transferrin receptor, alpha-tubulin and alpha-interferon in at least five of six helper T-cell lymphoproliferative disorders, while five of five suppressor T-cell disorders demonstrated levels of hybridization to these clones no higher than background. However, studies of T-suppressor disorders demonstrated enhanced levels of beta-interferon-specific RNA in five of five patients, an increase apparent in three of six T-helper chronic lymphoproliferative disorders. These results demonstrate different patterns of gene expression evident in T-helper and T-suppressor abnormalities.