RASGRF1 and rheumatoid arthritis: In non-RA patients, no significant association between RasGRF1 and MMP-1 (synovial sublining: R = 0.17, P = 0.703; intimal lining layer: R = -0.89, P = 0.083) or MMP-3 (synovial sublining: R = 0.83, P = 0.058; intimal lining layer: R = -0.20, P = 0.917) expression was observed (data not shown).