PALB2 and breast cancer: After CHEK2, PALB2 was the most frequently involved, with 6 out of 340 compared with none in our case set despite PALB2 having a potential founder effect in our region.12 The additional panel beyond CHEK2 of definitive breast cancer genes only identified a further 9 out of 340 (2.6%) in the German study with ATM the most frequent (n=6).