SRI and breast cancer: Sorcin overexpression by gene transfection (i) resulted in increased drug resistance to a variety of chemotherapeutic agents, including doxorubicin, etoposide, homoharringtonine and vincristine in K562 cells; and (ii) determined drug resistance to vincristine, adriamycin, taxol and 5-fluorouracil in SGC7901 cells, ovarian and breast cancer.