In many countries, women with DCIS do not qualify for genetic testing despite studies (including ICICLE [50]) showing a strong association with BRCA2 and CHEK2 mutations and a weaker association with PALB2, BRCA1, and TP53, although the frequency of BRCA mutations appears to be less frequent in DCIS than invasive disease [51,52]. Here, CHEK2 is linked to ductal breast carcinoma in situ.