IL4 and leprosy: Moreover, consistent with the results in the leprosy patients and cell infection model, Gpnmbfl/fl Lyz2-Cre mice infected with M. marinum expressed and secreted more pro-inflammatory cytokines, such as IL-6, TNF-α, IL-1β and IFN-γ, and fewer anti-inflammatory cytokines, such as IL-4 and IL-10, both on day 14 and day 21 post infection (Fig. 2E, F).