ARG1 and pachyonychia congenita: Furthermore, GCSFR−/− mice exhibit a shift in the immune profile of PC tumors from a TH-2 to TH-1 immune response, characterized by increased expression of IFN-γ, TNF-α and IL-12 with decreased expression of arginase-1, IL-6, TGF-β, IL-10 compared to WT mice (Fig. 2d).