ABCG2 and breast adenocarcinoma: Its effects have been reported towards several cancer cell lines including sensitive and resistant phenotypes such as CCRF-CEM cells and CEM/ADR5000 leukemia cells, MDA-MB-231-pcDNA and MDA-MB-231/BCRP breast adenocarcinoma cells, HEK293 and HEK293/ABCB5 embryonic kidney cells, and U87.MG and U87.MGΔEGFR glioblastoma cells with IC50 values ranging from 15.1 μM (against HEK293 cells) to 29.4 μM (towards CCRF-CEM cells) [34, 36].