(A) The landscape of co-occurring mutations in all patients with evaluable POLE mutations (n = 450). The most common co-occurring mutations included TP53 (52%), ARID1A (22%), BRCA2 (21%), KRAS (21%), NF1 (19%), NOTCH3 (18%), NOTCH1 (18%), ATM (18%), PIK3CA (17%), SETD2 (17%), and SMARCA4 (17%). Mutations are classified as pathogenic (green), benign (blue), and VUS (orange). Patients with pathogenic POLE mutations had more comutations in DDR genes as shown in the (B) heat map and (C) bar graphs above. DDR, DNA damage response; VUS, variant of unknown significance.