The two allelic variants of BRCA2 were found in blood, skin tissue, and in three primary tumor samples: invasive ductal carcinoma (IDC), contralateral ductal carcinoma in situ (DCIS), and colorectal cancer (CRC) identified during a necropsy study (Table 1, Fig. 3A–D and Figure S1A). Here, BRCA2 is linked to ductal breast carcinoma in situ.