A study on a hepatocarcinoma cell line (HCC) and breast cancer treated with Doxorubicin has revealed drug resistance, which was thought to happen via the induction of the multidrug‐resistant protein‐1 (MDR‐1) belonging to the ATP‐cassette binding protein family (ABC transporters) which occur due to changes in the tumor microhabitat and its associated signaling cascades. The gene discussed is ABCB1; the disease is breast carcinoma.