Increased capillary activity leads to massive release of nitric oxide (NO) which results in the degradation of regulator of G-protein signaling 4 (RGS4), thus activating G protein-coupled receptor (GPCR) mediated downstream signaling pathways such as PI3K and mTOR to promote cardiac hypertrophy (Jaba et al., 2013; Oka et al., 2014). This evidence concerns the gene RGS4 and cardiac hypertrophy.