Given the effectiveness of mavacamten to inhibit beta-cardiac myosin contractility (20) and help patients with hypertrophic cardiomyopathy (21), we hypothesized that mavacamten protects the heart through sequestering of myosin heads in the inactive SRX biochemical state, which is outside of the mechanochemical cycle. The gene discussed is MYH14; the disease is hypertrophic cardiomyopathy.