In our study, we found that while circulatory MDSC levels could not distinguish between pathologic responders and non-responders to nCRT, the analysis of tumor samples from patients with LARC before nCRT revealed significantly lower frequencies of intratumoral CD33+HLA-DR−CD16−CD11b+ MDSCs in patients responding to the treatment compared with non-responders. This evidence concerns the gene CD33 and neoplasm.