Among actin regulatory proteins which nucleate the assembly of unbranched actin filaments, the Formins and in particular the two Formin family members, diaphanous-related formin 1 and 3 (DIAPH1 and DIAPH3) have a crucial role in TGFβ-induced EMT in several tumor cells (i.e., lung, mammary, and renal epithelial cells) [168,210]. The gene discussed is DIAPH1; the disease is neoplasm.