Immunoblotting analysis of cyclin D1 and D3 protein abundance in total cell extracts of various exponentially proliferating human cells. Upper panel, cyclin D1 detection with the MoAb DCS-6; lower panel, cyclin D3 detected with the MoAb DCS-22. Cell types examined were PHA-stimulated normal lymphocytes (lane 1); WI38 diploid fibroblasts (positive control, lane 2); B-cell lymphoma lines harboring the t(11; 14) translocations JVM-2 (lane 3), K620 (lane 4), NCEB-1 (lane 5), and SP-49 (lane 6); MOLT-4 T-cell leukemia line (lane 7); and B-cell lymphoma lines lacking the t(11; 14) translocations Ramos (lane 8), Daudi (lane 9), and Namalwa (lane 10). Note the reciprocal expression of cyclins D1 and D3 among the lymphoma/leukemia-derived cell lines (lanes 3 to 6 versus lanes 7 to 10). The molecular weight of the markers is given in kilodaltons.