ITGAM and neoplasm: MDSC were further classified based on the expression of Ly6C and Ly6G as previously described14, and we found that the percentage of CD11b+ Ly6G+ decreased after radiotherapy in the parental tumor, with an increase of CD11b− Ly6C+ population, and the CD11b− Ly6C+ population was much higher in the parental tumor than the resistant tumor after radiotherapy (Fig. S2).