In our opinion, three key findings demonstrate the involvement of L-cysteine/CSE-CBS/H2S in the physiopathological mechanisms of SKM: (i) a low-cysteine diet regimen in CSE-deficient mice led to acute lethal myopathy [20]; (ii) hypercontractile SKM can be observed in patients prone to malignant hyperthermia, coupled to higher levels H2S and overexpression of CBS [19]; (iii) CBS-deficient mice with hyperhomocysteinemia showed an SKM dysfunction [21]. The gene discussed is CBS; the disease is hyperhomocysteinemia.