MRC1 and hyperinsulinemic hypoglycemia, familial, 4: Similarly, the same MSH6 knockouts made in the 125Q iPSC line (Figure S2C) resulted in the most robust survival post-6TG or MNNG treatment, indicating that the effect seen upon lowering by CRISPRi in iPSCs likely does not represent the maximal MMR deficiency possible in each case (Figures 3D, 3E, and S2D–S2F).