It has been reported that TRAIL responsiveness correlates with a reduced expression of endogenous Akt in MDR-U2OS human osteosarcoma cell line [24], and P-gp enhances TRAIL-triggered apoptosis by interacting with the death receptor DR5 in the MDR1-transfected MCF-7 breast cancer cell line [25]. This evidence concerns the gene PGP and breast carcinoma.