CHEK2 and breast carcinoma: A multicentre association study involving more than 113 000 women associated truncating variants in CHEK2 with an increase in breast cancer risk [odds ratio of 2.13 (1.60–2.84)] furthermore influenced by the ER status of the tumor [ER+ tumors 2.67 (95% CI, 2.3–3.11)] (9).