IL33 and gastritis: Recently, epithelial-derived WAP four-disulfide core domain 2 WFDC2 was shown to induce SPEM via an IL-33-dependent promotion of M2 macrophage polarization; specifically, using chemically induced gastritis mouse models, the absence of Wfdc2 results in reduced M2 infiltrates and no progression to SPEM and dysplasia, while the administration of rWFDC2 or recombinant IL-33 restores the development of SPEM [114].