STAT3 and diffuse large B-cell lymphoma: We have reported that prostaglandin D2 synthase (PTGDS) promotes the tumorigenesis of diffuse large B-cell lymphoma (DLBCL) by MYH9-mediated regulation of Wnt-β-catenin-STAT3 signaling [11], and previous studies found that PTGDS was involved in tumor development through regulating MAPK pathway [12], PPARγ [13] and STAT3 phosphorylation [14].