Such findings in LatY136F μMT mice are reminiscent of the marked reduction of Tfh cells and CD4+ CTL numbers observed in IgG4-RD patients following B cell depletion with the anti-CD20 antibody rituximab (Katz and Stone, 2022; Perugino and Stone, 2020). This evidence concerns the gene CD4 and immunoglobulin G4-related sclerosing disease.