IRF1 and neoplasm: Consistent with the in vitro cell experiments, we observed that PTP 9 and anti-PD-1 cotreatment induced a significant increase in tumor expression of Cxcl11, Ccl5, Stat1, Stat3, Tap1, Irf1, Casp8, and Pdl1, compared with anti-PD-1 treatment alone (Fig. 3F).