The assessment of HDL functions, such as cell culture-based assays used in general [29], was not performed in these studies, although one study [12] showed a low concentration of serum lecithin-cholesterol acyltransferase (LCAT: seemingly one of the markers related to HDL functions) in patients with rheumatoid arthritis and the PON1 level to correlate with the LCAT level in these patients. This evidence concerns the gene PON1 and rheumatoid arthritis.