Complex sentence: Although this protein was earlier thought to be a receptor for vasoactive intestinal peptide (VIP) and was considered to be an orphan receptor, it has been later been shown to bind the chemokines CXCL12/SDF-1 and CXCL11.
Split into simpler sentences: Although this protein was earlier thought to be a receptor for vasoactive intestinal peptide (VIP) and was considered to be an orphan receptor. It is now classified as a chemokine receptor able to bind the chemokines CXCL12/SDF-1 and CXCL11.