MRC1 and hyperinsulinemic hypoglycemia, familial, 4: Eleven cases received matched therapy based on IHC; ERBB2 positivity, trastuzumab (n = 5); PTEN loss (n = 2), PI3Kβ inhibitor; MMR deficiency (n = 2), PD-1 inhibitor; and EGFR positivity (n = 2), pan-ERBB inhibitor.