In relation to the STAT4 rs3821236 and rs7574865 polymorphisms, there was a higher heterogeneity in the reported ORs [36,37,38,39,40] (Table 3), with some autoimmune diseases showing considerably stronger signals than others (e.g. OR > 1.40 for SLE and 1.16 for RA). Here, STAT4 is linked to autoimmune disease.