Beyond diseases where gut-derived cells have been implicated, blockage of CCR5 expression has been evaluated as a treatment in cases where it is used as a co-receptor by a pathogen (HIV, Staphylococcus aureus) or a potential driver of aberrant inflammation (rheumatoid arthritis, IBD, MS, cancer) (21, 41). The gene discussed is CCR5; the disease is rheumatoid arthritis.