TPM1 and neoplasm: Several lines of evidence suggest that high molecular weight (HMW) TMs encoded by TPM-1 (α-TM) and TPM-2 (β-TM) genes[51] may contribute to the tumor suppressor activity of TGF-β.[52] Bakin et al.[52] reported that induction of TMs and stress fibers play an essential role in TGF-β-control of cell motility, and the loss of this TGF-β-response is a critical step in the acquisition of a metastatic phenotype by tumor cells.