PDGFA and cardiac hypertrophy: For example, the transgenic expression of the natural isoforms of Pdgfa and b under the α-myosin heavy chain (α-MHC) promoter has shown severe fibrotic reactions, increase in cardiac size, and cardiac failure a week after birth, whereas overexpression of Pdgfb showed focal fibrosis and cardiac hypertrophy (Gallini et al., 2016b).