In addition, in an animal study using SKG mice harboring a microbiota dominated by Prevotella copri from RA patients, interleukin-17 (IL-17) was increased with a higher number of intestinal Th17 cells, which response to the arthritis-related autoantigen 60S ribosomal protein L23a (RPL23A) in the lymphocytes of regional lymph nodes and the colon, leading to the development of arthritis. This evidence concerns the gene IL17A and rheumatoid arthritis.