IDH1 and cancer: Arginine to histidine mutations that mediate altered pH-dependence of activity, and could be related to fitness advantage in cancer cells include EGFR-R776H and p53-R273H [20], and IDH1-R132H where production of the oncometabolite D-2-hydroxyglutarate is rendered pH-dependent if mutant and wild type IDH1 form a heterodimer [21].