KRT15 and ductal breast carcinoma in situ: Of the 208 cores, 38 (18%) were excluded because they were not suitable for evaluation: ductal carcinoma in situ (23 cores; A5, A6, A11, A12, C1, C2, C10, C14, C15, C16, D7, D9, D10, F8, G15, G16, H3, H4, I7, I8, J3, M15 and M16), DAB judgment not possible by insufficient fixation (8 cores; F3, F4, E13, E14, K11, K12, L1 and L2), cytoplasmic staining (2 cores; L7 and L8), no cancer (3 cores; H15, K15 and K16), and core peeling (2 cores; B4 and E5).