COL1A1 and hypertrophic cardiomyopathy: Moreover, Col1α1 and Col3α1 gene expression was inversely correlated with the level of miRNA-26a, previously reported to inhibit collagen expression in cardiomyocytes and fibroblasts under conditions of ischemic and hypertrophic cardiomyopathy but never reported to be affected by estrogen or a menopausal state [20].