CD4 and neoplasm: Moreover, both proinflammatory (e.g., M0 macrophages, neutrophils and memory B cells) and immuno-modulating (e.g., CD8+ and CD4+ T lymphocytes, naïve B cells, monocytes, plasma cells, and activated mast cells) leukocyte populations abundantly reside into PDAC TME, with the latter being more abundant in tumor samples from patients with worse prognosis (14).