PGP and hepatocellular carcinoma: • Inhibits lysosomal exocytosis independent of Pgp and promotes doxorubicin cytotoxicity in rhabdomyosarcoma cells (Machado et al., 2015). • Promotes vascularization/angiogenesis in lung and pancreatic cancer; combination therapy improves gemcitabine cytotoxicity (Wong et al., 2015). • Potentiates sorafenib cytotoxicity in hepatocellular carcinoma (HCC) cells (Colombo et al., 2014).