Here, we review recent findings in the Lrrc10−∕− mouse and human idiopathic DCM patients that implicate LRRC10 in the pathogenesis of DCM, discuss molecular alterations in the Lrrc10−∕− heart that may contribute to cardiomyopathy, and preface ongoing work investigating the molecular function of LRRC10. The gene discussed is LRRC10; the disease is familial dilated cardiomyopathy.