In agreement with our histological analyses of Col19a1 nullizygous mice, which showed no evidence of myocardial fibrosis, siRNA-mediated depletion of Col19a1 had no effect on mRNA levels of key structural collagens (Col1a1, Col3a1, and Col4a1), relative to non-target-transduced controls (siNT) (Fig. 5A,B). Here, COL3A1 is linked to Myocardial fibrosis.