In one paper, archived neonatal blood was analyzed with immunoaffinity chromatography and serum levels of vasoactive intestinal peptide (VIP) and calcitonin-gene related peptide (CGRP) were higher in children with ASD (n = 69) and those with mental retardation without ASD (n = 60); in contrast, levels of substance P (SP) and nerve growth factor (NGF) were similar to those of controls [10]. The gene discussed is VIP; the disease is Intellectual disability.