Interestingly, as evidenced in a knock-in mouse model of LS, as well as in cell lines derived from individuals with LS, LS mutations seem to result in blocked activation of MAPK but increased activation of AKT downstream of receptor tyrosine kinases (Edouard et al., 2010; Marin et al., 2011). The gene discussed is NTRK1; the disease is Leigh syndrome.