MAPK3 and familial dilated cardiomyopathy: Patient-specific iPSC-derived CM models of LMNA-DCM have shown nuclear blebbing and apoptosis (Siu et al., 2012), ERK1/2-dependent phosphorylation of cofilin (Chatzifrangkeskou et al., 2018), epigenetic suppression of SCN5A expression (Salvarani et al., 2019), and PDGF-dependent perturbation of calcium signaling (Lee et al., 2019).