For example, oleuropein, a glycosylated seco-iridoid from green olives, was shown to act as a radiosensitizer toward nasopharyngeal carcinoma both in vitro and in vivo; the radiosensitizing action was associated with the inhibition of HIF-1α/miR519d/p53 and the DNA damage-regulated protein 1 (PDRG1) pathway in oleuropein-treated cancer cells [99]. Here, HIF1A is linked to cancer.