The pattern of TGF-beta mRNA expression and response to TGF-beta isoforms has been examined in three lung squamous carcinoma cell lines (NX002, CX140 and CX143). Expression for TGF-beta1 and TGF-beta2 but not TGF-beta3 was found in all 3 lines. TGF-beta1 and TGF-beta3 (but not TGF-beta2) inhibited the growth of the NX002 cell line in culture. The effect of TGF-beta1 on growth was accompanied with changes in the cell cycle. These data indicate that the potential for autocrine regulation by TGF-beta is present in lung squamous carcinoma cells.