While the central role played by TGFβ in regulation of SMC differentiation has been previously demonstrated (Lindner & Reidy, 1991; Hirschi et al, 1998; Kawai‐Kowase et al, 2004), little is known about what regulates this pathway and what contribution SMC proliferation makes to progression of lesions seen in atherosclerosis (Tabas et al, 2015). The gene discussed is TGFB1; the disease is atherosclerosis.