ATM and nasopharyngeal carcinoma: The overall frequency of HR‐DDR mutations detected was 17.4%; ARID1A was the most commonly mutated gene (7.2%), followed by BRCA2 (3.0%), BRCA1 (2.8%), ATM (1.3%), ATRX (1.3%), and CHEK2 (1.3%) [30], indicating that more BRCAness genes like ARID1A within the HRR pathway are crucial for maintaining genomic stability in NPC.