Ductal carcinomas had lower levels of Nectin-3 but not Nectin-4, (Nectin-3: ductal 1534+/−1177 versus other 2581+/−1699, p = 0.6; Nectin-4: ductal 0.30+/−0.15 versus other 0.022+/−0.021, p = 0.074). Here, NECTIN4 is linked to breast ductal adenocarcinoma.