Encouragingly, co-culturing of 4T1 cells with RAW 264.7 macrophage cells in an arginine-depleted medium supplemented with IFNγ significantly increased pSTAT1 levels in cancer cells relative to culturing in full medium, supporting a role for macrophages in enabling the induction of JAK-STAT signaling in tumor cells under arginine depletion (Figure 4A). Here, IFNG is linked to cancer.