passages.id: split_1_test_2801_passage
passages.type: progene_text
passages.text: IL-1 and tumor necrosis factor ( TNF ) enhance the serine phosphorylation of Stat1 that occurs in response to interferon-gamma ( IFN-gamma ) and potentiate IFN-gamma - mediated , Stat1 - driven gene expression , thus contributing to the synergistic activities of these proinflammatory cytokines .