MAST4, AHDC1, BICC1, USP16, IQCK, LOC727677, MYO1D, LOC441897, CAV2, and TGFBR2 exhibited hypermethylation while TMEM9B, CLIC6, CCS, PAWR, FIP1L1, ARHGAP15, ARHGAP26, PKD1L1, HLA-DRB1, and HLA-DQB2 exhibited hypomethylation at CpG sites in CD4+ T cells from IgG4-RD patients. Here, BICC1 is linked to immunoglobulin G4-related sclerosing disease.