Male Npr1 0-copy and 1-copy mutant mice treated with GW788388 showed attenuated levels of interstitial cardiac fibrosis by almost 65–70% (p < 0.001) in 0-copy and 40–45% (p < 0.001) in 1-copy male mice compared with untreated control mice (Figure 7A,B). This evidence concerns the gene NPR1 and Interstitial cardiac fibrosis.