ACTA1 and Myocardial fibrosis: Although activation of the fetal gene program is generally observed in pathological forms of hypertrophy, it is of interest that in the dn-c-kit-Tg hearts, hypertrophy occurred in the absence of other markers of pathological hypertrophy, such as decreased Myh6 expression and increased Acta1 expression, myofibrillar disarray, increased myocardial fibrosis, altered capillary density or increased apoptosis.