Analyses of Tfh cell transcriptomes together with multicolour immunofluorescence from IgG4‐RD tissues showed that BATF+ (a transcription factor regulating IL‐4 secretion) Tfh cells had greater expansion in the IgG4‐RD cohort than in control secondary lymphoid organs [82]. This evidence concerns the gene BATF and immunoglobulin G4-related sclerosing disease.