MPIG6B and rheumatoid arthritis: CCL+ memory B cells from ACPA- RA patients were additionally transcriptionally distinct, being enriched for “immunoglobulin receptor binding”, “antigen binding”, and “protein processing in endoplasmic reticulum” but lower for “glycolysis/gluconeogenesis”, “phagosome”, and “antigen processing and presentation activity” (Fig. 3c).