NPPA and familial dilated cardiomyopathy: Although protein levels of atrial natriuretic factor were increased in both patients with DCM and those with IHD compared with controls (fold change, 2.84, P<0.001; and fold change, 2.31, P=0.019) and inversely correlated to SERCA2a (Spearman Rho=−0.48, P<0.001), we detected no significant changes in SERCA2a or PLN protein abundance between DCM, IHD, and control hearts (Figure [D]).