Interestingly, the expression of DNA‐PK and functional markers of MDSCs (iNOS, Arg1, and IDO) were significantly increased in splenic MDSCs of tumor‐bearing mice treated with NU7441 in vitro (Figure 6A–D), suggesting that NU7441 significantly increased the expression of DNA‐PK and the immunosuppressive function of MDSCs. Here, ARG1 is linked to neoplasm.