TMEM187 and rheumatoid arthritis: Therefore, the present study aimed at investigating the association between critical polymorphisms in Xq28, from rs13397 (A/G) through rs1059703 (C/T) and rs1059702 (C/T) in the TMEM187 and IRAK1 locus, respectively, with risk for RA in two not previously studied populations displaying different genetic background: Tunisian and French.