ABCB1 and osteosarcoma: A phase II trial of trabectedin in relapsing osteosarcoma patients did not improve survival, however, though the authors suggested it may be useful in combination with doxorubicin and cisplatin due to its ability to suppress MDR1 expression by inhibition of the orphan nuclear receptor steroid and xenobiotic receptor (SXR) [141,142,143] (see resistance section).