IFNB1 and familial dilated cardiomyopathy: However, the levels of IFNβ1 downstream genes (IFIT1, IFIT3, RSAD2 and IRF7) were negatively correlated with kshv-miR-K12-1-5p expression in DCM hearts (Supplementary Fig. 11), suggesting that type I IFN signaling pathway was disrupted not only in local hearts, but also systemically, in DCM patients with higher kshv-miR-K12-1-5p levels.