IL13 and neoplasm: Under conditions of chronic inflammation, IFN-γ secretion by Th1 lymphocytes seems to play a pivotal role in preventing tumor cell proliferation, while IL-13 derived from Th2 lymphocytes and TNF-α, IL-6, and IL-17 produced by Th17 cells promote dysplastic cell proliferation and tumor growth (Rizzo et al., 2011).