STAT1 and cancer: Apigenin, a flavonoid derived from onions, oranges, or chamomile tea, can attenuate IFN-γ- or IFN-β-induced PD-L1 upregulation in cancer cells by blocking the signal transducer and activator of the transcription 1 (STAT1) pathway, resulting in enhanced T-cell-mediated cancer cell death [86].