STAT3 and helminthiasis: In the process of M2 polarization and helminth infection, the immune response of the host to helminth infections is strikingly dominated by a Th2 response with a significant production of IL-4, IL-10, IL-13 (Pulendran and Artis, 2012), and the STAT3/STAT6 signaling pathways have been detected (O’Shea et al., 2002; Schindler et al., 2007).