Compared with their respective control littermates, tamoxifen-induced cardiac myofibroblasts-specific cGKI knockout (cmfKO) mice developed significantly increased cardiomyocyte cross-sectional areas, a marked increase in myocardial fibrosis, as well as a significant structure-related distortion of global systolic heart function. Here, PRKG1 is linked to Myocardial fibrosis.