PTPN11 and Leigh syndrome: Carvajal-Vergara et al. [133] have generated CMs from patients with LEOPARD syndrome (LS) which causes hypertrophic cardiomyopathy due to mutations in the protein tyrosine phosphatase nonreceptor type 11 (PTPN11) gene encoding the protein tyrosine phosphatase containing a Src homology 2 domain (SHP2) phosphatase protein which is involved in rat sarcoma mitogen-activated protein kinase (RAS-MAPK) signalling.