Two variant KI animals were reported simultaneously by different laboratories, each carrying a different genetic variant in a DCM-associated hotspot in exon 9 (c.1881–1920 in humans) (Parikh et al. 2019), which encodes a portion of the arginine/serine-rich (RS) domain in RBM20. The gene discussed is RBM20; the disease is familial dilated cardiomyopathy.