More recently, molecular classification has further subdivided EC into four groups: EC with polymerase epsilon mutations (POLEmut), EC with mismatch repair deficiency (dMMR), high microsatellite instability (MSI-high), EC with TP53 mutations and abnormal p53 protein expression (p53abn), and EC without a specific molecular profile (NSMP) [6]. Here, TP53 is linked to hyperinsulinemic hypoglycemia, familial, 4.