Intriguingly, classical M2 markers including Cd206 (Mrc1), Cd163, Pdl2 (Pdcd1lg2), Ccr3, Arg1 and many others were all markedly downregulated in TAMs isolated from the St2−/− background as compared with those isolated from tumours grown in wt mice (Fig. 5c and Supplementary Fig. 5c). Here, ARG1 is linked to neoplasm.