Therefore, although the histopathological manifestations and constellation of pathogenic lymphoid cells at play in LatY136F DLSP and IgG4-RD are strikingly similar, the underlying molecular malfunctions intrinsic to conventional CD4+ T cells and responsible for the etiology of the LatY136F DLSP and IgG4-RD likely differ. This evidence concerns the gene CD4 and immunoglobulin G4-related sclerosing disease.