In this study, it was found that DNA‐PK levels in MDSCs, PMN‐MDSCs, and Mo‐MDSCs in tumor‐bearing mice PBMCs were lower than those in healthy mice, while pDNA‐PK (a post‐translational modification positively correlated with the kinase activity of DNA‐PK) levels were higher, which was consistent with the latter conclusion. This evidence concerns the gene PRKDC and neoplasm.