ANGPTL4 and rheumatoid arthritis: The RA cohort comprised 2 sub-groups based on the serum level of ANGPTL4; ‘low ANGPTL4’ (≤170 ng/ml, serum ANGPTL4 within the normal range) and ‘high ANGPTL4’ (>170 ng/ml; serum ANGPTL4 more than 10% above normal range).