ARG1 and neoplasm: To further confirm that Cat S-mediated autophagy plays an important role in macrophage polarization in the tumor microenvironment, we treated WT or Cat S-/- macrophages with the autophagy inhibitor chloroquine (CQ) prior to coculture with SL4 cells, and assayed the expression of M2-type genes (arginase-1, Arg-1; found in inflammatory zone protein, FIZZ1 and interleukin-10, IL-10) and M1-type genes (inducible nitric oxide synthase, iNOS; interleukin-1β, IL-1β and tumor necrosis factor-α, TNF-α).