IL12B and rheumatoid arthritis: The IL12B gene is an autosomal recessive gene and as per log additive model, the expression of minor allele ‘A’ in the diseased group only, might be a risk allele in the off springs of diseased heterozygous (CA) genotype carriers in homozygous pattern of inheritance with positive history of consanguinity and positive family history of RA in first degree relatives as important risk factors.