NPPB and familial dilated cardiomyopathy: There was a ~40% reduction in serum FGF1 levels in the patients with DCM compared to the patients without DCM (Fig. 1a), and serum FGF1 levels were positively correlated with the fractional shortening (FS) (Fig. 1b) and negatively correlated with the serum brain natriuretic peptide (BNP) (Fig. 1c).