CHEK2 and breast cancer: A study by the BC Association Consortium (2021) found that protein-truncating variants in ATM (OR = 2.10, 95% CI: 1.71–2.57; p < 0.0001) and CHEK2 (OR = 2.54, 95% CI: 2.21–2.91; p < 0.0001) were associated with a 2.0- to 2.5-fold increased risk of BC [39].