ABCB4 and breast carcinoma: We therefore treated the lung cancer cell lines A427, A549, H322, HCC-15, HTB171 and H1299, the breast cancer cells ZR-75-1, the HN cancer cell RPMI-2650 and the melanoma cells SK-Mel-13 with Aza or Zebu and analyzed the ABCB4 expression (Fig. 4).