ARG1 and neoplasm: In addition, our qPCR results suggested that NU7441 could increase the mRNA expression of DNA‐PK and functional markers of MDSCs (iNOS, Arg1, IDO) in the splenic MDSCs of tumor‐bearing mice in vivo and in vitro suggesting that the effect of NU7441 alone on DNA‐PK in tumor‐bearing mice MDSCs may be different from previous studies.