CD8A and neoplasm: Of notice, while MCs exert pro-tumor activities in WD adenocarcinomas, by producing MMP-9 [96] and suppressing CD8+ T cell response [96] (Figure 2B), via crosstalk with polymorphonuclear (PMN)-MDSCs, MCs have been found to acquire protective functions by interfering with de novo generation of neuroendocrine tumors [94, 96, 97] (Figure 2C).