HIF1A and nasopharyngeal carcinoma: OLE and HT cytotoxic actions themselves in part depend on ROS generation [57,59,63,75,85,88,101,102]; moreover, 200 μM OLE reduced HIF-1α mRNA and protein levels in HNE-1 and HONE-1 nasopharyngeal cancer cell lines [278], and pro-apoptotic OLE concentration corresponding to 100 μM was able to increase ROS production in MDA-MB-231 cell line, with the maximum peak obtained after 4 h incubation [51].