CHEK2 and breast cancer: In particular, five (9.4%) out of 53 PV-positive BBC patients have been shown to harbor CHEK2 PVs, eight patients (15.1%) showed PALB2 PVs, three individuals (5.7%) carried ATM PVs, only one patient (1.9%) exhibited a PTEN PV, while PVs in RAD51C were detected in two (3.8%) triple-negative BC patients (Table 3).