The production of IL10 in IBD, RA and SLE dictates their course: while in SLE patients IL10 favours B cell differentiation and autoantibody production as shown in the SYSCID map (see pathway “IL10-mediated B cell differentiation”), a dysfunction of IL10 production makes mice prone to spontaneous colitis (103, 104). This evidence concerns the gene IL10 and systemic lupus erythematosus.