TPCN1 and familial dilated cardiomyopathy: These results were confirmed at the protein level: TPCN1 expression was increased significantly (p = 0.002) in DCM (n = 13) relative to CTL (n = 4) and TPCN2 expression was increased significantly in ICM (n = 8; p = 0.016) and DCM (n = 6; p = 0.031) relative to CTL (n = 4) (Table 3 and Fig. 3).