NFKB1 and juvenile idiopathic arthritis: After stratification based on the sex of the patients, similar significant differences for the NFKB1 rs28362491*DD genotype were found only in girls with JIA (P = 0.017, pcor = 0.017, OR = 2.846, 95% CI 1.253–6.483), and only a similar trend was observed in boys with JIA (pcor = 0.085), which is probably due to the smaller sample size.