Transcription factor. It inhibits binding to DNA and transcriptional transactivation by heterodimerization with bHLH protein. Expressed in small cell lung cancer. It is deregulated in ALL with t(6;14), gastric adenoca, and bladder cancer. Part of TGF-β pathway. Possible tumor suppressor gene. This evidence concerns the gene TGFB1 and acute lymphoblastic leukemia.