VPAC1 and VPAC2 both mediate anti-inflammatory and immunoregulatory responses in RA. Both these are receptors of vasoactive intestinal peptide (VIP), a broadly distributed peptide found in neural, endocrine and immune cells, which triggers biological response when interacting with the aforementioned receptors. It has recently been described in Martinez et al. that those patients with low levels of VIP have worse disease outcome.1This study analyzed 250 blood samples from the Princesa early Arthr...