NOS2 and neoplasm: Similar to our results in naïve mice, we found a strong downregulation of Nos2 expression in Stat1 deficient M1 macrophages derived from tumor bearing mice (Figure 4F) as well as decreased secretion of soluble TNFα in the supernatant derived from M1 macrophages differentiated from tumor bearing STAT1 KO mice (Figure 4G).