IL21 and Arthritis: Interestingly, when performing enrichment analyses of the list of genes encoding such 80 proteins (Supplementary Table 7), we found a highly significant enrichment in genes that are either associated with immune-related terms, as identified by text mining (“immune System”, “NFKB complex”, “arthritis” and others), or linked to immune biological processes according to the GO term classification (“cellular response to IL-21,” “cellular response to IL-2” and others).