Genetic variations of another key factor for B cell survival and maturation, BAFF, have been analyzed, leading to the conclusion that in patients with rheumatoid arthritis, homozygous C/C genotypes of BAFF promoter at position 871 (rs9514828) are associated with a superior response to rituximab than T/T genotypes [88]. The gene discussed is TNFSF13B; the disease is rheumatoid arthritis.