In addition, we identified four major peripheral B cell subsets: IL4R+ IGHD+ naive B cells (Naive BCs); CD27+ IGHG1+ memory B cells (Memory BCs); plasma cells or so-called antibody-secreting cells (ASCs), expressing high level of immunoglobulin genes MZB1; and a subset of ITGAX+ B cells defined as age-associated B cells (ABCs) (Fig. S3L).