As we know, some emerging prognostic factors in DLBCL are the immune system and vitamin D. This is the reason why we decided to evaluate the evolution of immune response suppressor cells, such as MDSCs, Tregs, and both inhibited PD-1+OX40− and CTLA-4+OX40− T cells in R/R DLBCL patients with deficit and normal levels of vitamin D levels using R2-GDP as an immunomodulator in the R2-GDP-GOTEL study (EudraCT Number: 2014-001620-29). This evidence concerns the gene PDCD1 and diffuse large B-cell lymphoma.