IL4 and parasitic infectious disease: In contrast, upon stimulation by cytokines such as interleukin-4 (IL-4), interleukin-13 (IL-13), interleukin-10 (IL-10), and transforming growth factor-beta (TGF-β), macrophages are polarized into the M2 phenotype, which can be further subdivided into M2a, M2b, M2c, and M2d subtypes, contributing to anti-inflammatory responses, tissue repair, and parasitic infections (7, 8).