KRT15 and breast carcinoma: On western blotting using lysates derived from N/Tert-1, a K15+ cell line31 and MCF-7, a K15- human breast carcinoma cell line32, grown in 2-dimensional (2-D) cultures, both antibodies recognised a single 50 kDa band only in N/Tert-1 but not in MCF-7 cells (Fig. 1B).