Multiple concentration ligand binding autoradiography is still a very useful tool to quantify the number (Bmax) and affinity (KD) of a variety of receptor types and was applied to this study investigating whether 5‐HTT and other major subtypes of 5‐HT receptors (5‐HT2 and 5‐HT1A) had significant changes in children and/or adult autism cohorts as compared to neurotypically developing individuals. The gene discussed is SLC6A4; the disease is autism.