IL4 and pulmonary fibrosis: Immune cells Th2 play a major role in the formation of late radiographic pulmonary fibrosis by inducing collagen synthesis to promote tissue remodeling and lung fibrosis, and Th2 stimulates B-cell proliferation and antibody production by secreting Th2-related cytokines, such as IL-4, IL-5, IL-6, IL-10, and IL-13, which play a major role in the formation of late-stage radiographic pulmonary fibrosis[49–52].