In addition to the suppressive effects on Th1 cells, the exposure of murine CD8+ cytotoxic T-lymphocytes to TGF-β1 in vitro was found to result in the attenuation of anti-tumor activity, which was associated with interference with the intracellular signaling mechanisms involving the transcription factors, ATF1 (cyclic AMP-dependent transcription factor 1) and Smads (suppression of mothers against decapetaplegic) [29]. The gene discussed is TGFB1; the disease is neoplasm.