CCL2 and immunoglobulin G4-related sclerosing disease: In pathway analysis of upstream genes identified by transcriptome analyses of GC-type Tfh cells in IgG4-RD lesions and tonsils (Figures 1B, 3B), a series of cytokines, including IL-2, IL-1β, CCL2, and IL-10, were postulated to be possible driver molecules related to the phenotype of lesional Tfh cells in IgG4-RD (Supplementary Table S8A).