Moreover, Pai-1 knockdown decreased the number of tumor alternatively activated macrophages (F4/80+/Arg1+) and Tregs (CD4+/FoxP3+) with a concomitant increase in CTL cells expressing granzyme B, suggesting a stronger antitumor cytotoxicity (Fig. 4, N and O, and fig. The gene discussed is ARG1; the disease is neoplasm.