However, apigenin interestingly increased NK cytotoxicity and the production of GrzB in a coculture of NK and HCC cells when HIF-1α was expressed (NK cytotoxicity; Fig. 1B; CoCl2 4.68%, CoCl2+apigenin 9.99%; *,**p < 0.05). The gene discussed is HIF1A; the disease is hepatocellular carcinoma.