IL12B and rheumatoid arthritis: Several gene polymorphism studies showed that IL-12B gene polymorphisms have an impact on RA pathogenesis, since, for instance, investigations in the Polish population showed that frequencies of the rs3212227 CC of the IL12B gene were statistically higher in RA patients compared to controls and that the IL12B 1188A/C allele as well as IL-12p70 protein levels are likely to be associated with RA (Paradowska-Gorycka et al., 2017[150]).