COL11A2 and rheumatoid arthritis: The SYSCID map shows which bacterial genera produce immunoregulatory small compounds in IBD, e.g., Roseburia and Faecalibacterium for butyrate and Bifidobacteirum for acetate, and mimic peptides in RA, i.e., Eggerthella, Clostridium, Bacteroides, Cryptobacterium, Actinomyces, Atopobium and Oribacterium for peptides like COL11A2 and HLA-DRB1*0401.