For the expression of the PDGF/PDGFR system in Asian and Western countries, 51 of 77 tests of RA and 21 of 65 nonarthritic subjects were recorded in Asian countries, while Western countries had 39 of 49 tests of RA patients and 6 of 32 tests of nonarthritic subjects. The gene discussed is PDGFRB; the disease is rheumatoid arthritis.