TNFRSF11B and rheumatoid arthritis: Interestingly, in a study by Zavala-Cerna et al., where the correlation of osteoprotegerin polymorphisms in a Mexican population with rheumatoid arthritis (RA) and osteoporosis was checked, the C allele of the rs207361 polymorphism was shown to be associated with RA, but the main premise of this study was not proven [29].