Furthermore, research continues being carried out in order to find new biomarkers for rheumatoid arthritis, including proteins as 14-3-3 η [164], enzymes as secretory phospholipase A2 group IIA (sPLA2-IIA) [165], or polymorphisms as rs688136 from the vasoactive intestinal peptide (VIP) gene [166], or rs13192471 from the HLA-DRB1 gene [167]. Here, VIP is linked to rheumatoid arthritis.