DRD2 and breast cancer: Given that no significant changes were observed in aripiprazole‐induced apoptosis in MCF‐7 cells pretreated with dibutyryl‐cAMP, an analog of cAMP that stimulates protein kinase A (data not shown), we next examined whether this antiapoptotic function of D2R activation during aripiprazole‐induced apoptosis involved the AMPK pathway in breast cancer cells.