ACTA1 and neoplasm: Expression of α smooth muscle actin (αSMA) is associated with subsets of “activated” (ie, profibrotic) fibroblasts in a variety of fibrotic pathologies and cancer types.38–40 Interestingly, in oral carcinoma, a subtype of CAFs with low αSMA expression was recently found to have an inhibitory effect on tumor proliferation and cancer cell self-renewal in vitro.41 Such results suggest a dual role for fibroblasts in tumors, with certain subpopulations encouraging tumor proliferation and other subpopulations involved in limiting it, both of which may be clinically targetable.