CD44 and neoplasm: We have limitations in studying the immune characteristics of TME in our TCCRP case, CD4+ T cells and CD8+ T cells in TILs contain multiple cell subpopulations, which need to be differentiated on the basis of surface markers and secreted cytokines, and each subpopulation plays a different role in the immune response, for example, Th1 cells promote tumour killing, Treg suppress the immune response, Th1 cell markers include CD28, CD44, secrete IFN-γ and the Treg cell marker is FOXP3.