Similar to gene_group1, the UV-light signature, the APOBEC signature (5.8% exposure), MMR deficiency signature (24.7% exposure), and POLE deficiency signature (19.6% exposure) were also identified in gene_group2 (mutated non-histone genes from the same set of patients) (Figure 2C). Here, POLE is linked to hyperinsulinemic hypoglycemia, familial, 4.