Some of these features may be: (1) formation of tertiary lymphoid structures, containing functional germinal centers where antigen-driven antibody responses may occur [51,52,53]; (2) infiltration by M2-type macrophages [54] and Tregs [55]; (3) modified Th2 microenvironment with expression of IL-10, IL-4, VEGF, and TGF-β [56]; and 4) detection of IgG4 antibodies and/or IgG4+ B cells [30,33,57], together with Tregs [56] and Bregs [58] in the tumor microenvironment (TME) [3]. Here, IL4 is linked to neoplasm.