Three human AIDS-NHL-derived cell lines representing distinct histologic subtypes, i.e., 2F7, BCBL-1 and UMCL01-101, were treated with IL-6, TGF-β1, or a combination of both cytokines for 0 to 6 days, and growth was measured at regular intervals by MTT assay (Figure 6). The gene discussed is TGFB1; the disease is AIDS.