CD8A and neoplasm: Furthermore, considering that most secondary CD8 T cell responses rely on CD4 T cell help (115), which is mediated by the antigen-presenting DC (1–4), it is conceivable to envision that CD4 TRM can license intratumoral DCs for productive restimulation of TRM and/or recirculating memory CD8 T cells infiltrating the tumor (Figure 3A).