The pattern of TGF beta expression and in vitro response to TGF beta has been defined in three ovarian carcinoma cell lines (PEO1, PEO4 and PEO14). Marked differences in both mRNA expression and growth responses were detected between the cell lines. All expressed mRNA for TGF beta 3, PEO1 and PEO4 but not PEO14 expressed mRNA for TGF beta 1, whereas PEO14 but not PEO1 and PEO4 expressed TGF beta 2. Growth of PEO14 cells in culture was markedly inhibited by both TGF beta 1 and beta 2. PEO1 cells were inhibited by TGF beta 1, but not TGF beta 2 whilst growth of PEO4 cells were not affected by exposure to either of these peptides. These data indicate that several elements of potential autocrine loops involving TGF beta's are present within ovarian cancer cells.