['Limited data are available on the genetics of rheumatoid arthritis (RA) in Egyptians. Therefore, we investigated whether the confirmed genetic risk factors for RA in Europeans and/or Asians contribute to RA susceptibility in Egyptians.', 'A set of seven single-nucleotide polymorphisms (SNPs) in the vicinity of CD28, TNFAIP3, PTPN22, PADI4 and HLA-DRA were tested in a large multi-centric RA cohort in Egypt, consisting of 394 cases and 398 matched controls. Patients were stratified based on the positivity of either anti-citrullinated protein antibodies (ACPAs) or rheumatoid factor (RF).', 'Significant association was evident for three SNPs in this cohort: the CD28 (rs1980422) variant showed a strong association in the whole cohort (P=0.000119) and in seropositive subsets of the disease (PACPA+=0.004; PRF+=0.0005). Upon stratification, the PTPN22 (rs2476601) and TNFAIP3(rs5029939) variants showed association only with ACPA positive (PACPA+=0.00573) and negative (PACPA-=0.00999) phenotypes, respectively.'] Are cD28 and PTPN22 associated with susceptibility to rheumatoid arthritis in Egyptians?