IFNG and neoplasm: HIF-1α accumulation was initially comparable in IFN-γ-treated and cobalt chloride-treated cells; however, after 1 h of cycloheximide exposure, this accumulation almost disappeared in the IFN-γ-treated tumor cells, suggesting that the stimulatory effect of IFN-γ on HIF-1α protein expression in BxPC-3 cells depends on protein synthesis, and not simply on increased protein stability.