BCL2 and ductal breast carcinoma in situ: To examine the functional relevance of BCL2 induction in the BM-localized tumor cells, we examined the effects of lapatinib treatment in combination with the dual BCL-2/XL inhibitor ABT-737.28 Mice bearing SUM225 DCIS-like tumors (n = 4–5 mice per group) were pre-treated with either vehicle or lapatinib [200 mg/kg/day per os (p.o.)] for 10 days followed by 5 days of either vehicle or lapatinib plus ABT-737 [70 mg/kg/day intraperitoneally (i.p.)].