NPNT and autoimmune disease: For clarification of Npnt function in autoimmune diseases, we generated a neutralizing antibody against Npnt (anti‐Npnt‐FD antibody) by immunizing rabbits with the PQKPRGDVFIPRQPTNDLFEIFEIER peptide (Npnt‐FD peptide), because the RGD motif and LFEIFEIER sequence in Npnt plays a critical role in the binding to its physiological receptor, α8β1 integrin 22.