TP53 and breast cancer: On a gene‐specific level, the CHEK2 c.1000del founder variant (2.5% vs. 1.3%; P = .018), deleterious variants in the PALB2 gene (2.2% vs. 1.1%; P = .020), and deleterious variants in the TP53 gene (0.79% vs. 0.24%; P = .035) were significantly associated with bilateral BC (Table 3).