<sod>Stimulation of this receptor subtype is also associated with [[growth hormone]] secretion. People with the inactive [[CHRNA4]] mutation Ser248Phe are an average of 10&nbsp;cm (4 inches) shorter than average and predisposed to [[obesity]].<ref>{{cite journal|pmid=18042647|year=2008|last1=Fedi|first1=M|last2=Bach|first2=LA|last3=Berkovic|first3=SF|last4=Willoughby|first4=JO|last5=Scheffer|first5=IE|last6=Reutens|first6=DC|title=Association of a nicotinic receptor mutation with reduced height and blunted physostigmine-stimulated growth hormone release|volume=93|issue=2|pages=634–7|doi=10.1210/jc.2007-1611|journal=The Journal of Clinical Endocrinology and Metabolism}}</ref><eod>
<sod>Stimulation of this receptor subtype is also associated with [[growth hormone]] secretion. People with the inactive [[CHRNA4]] mutation Ser248Phe are an average of 10&nbsp;cm (4 inches) shorter than average and predisposed to [[obesity]].<ref>{{cite journal|pmid=18042647|year=2008|last1=Fedi|first1=M|last2=Bach|first2=LA|last3=Berkovic|first3=SF|last4=Willoughby|first4=JO|last5=Scheffer|first5=IE|last6=Reutens|first6=DC|title=Association of a nicotinic receptor mutation with reduced height and blunted physostigmine-stimulated growth hormone release|volume=93|issue=2|pages=634–7|doi=10.1210/jc.2007-1611|journal=The Journal of Clinical Endocrinology and Metabolism}}</ref>  A 2015 review noted that stimulation of the α4β2 nicotinic receptor in the brain is responsible for certain improvements in attentional performance;<ref>{{cite journal|last1=Sarter M|title=Behavioral-cognitive targets for cholinergic enhancement|journal=Current Opinion in Behavioral Sciences|date=August 2015|volume=4|pages=22–26|doi=10.1016/j.cobeha.2015.01.004}}</ref> among the nicotinic receptor subtypes, [[nicotine]] has the highest [[binding affinity]] at the α4β2 receptor (k<sub>i</sub>=1&nbsp;{{abbr|nM|nanomole}}), which is also the biological target that mediates nicotine's [[addictive]] properties.<ref name="Nicotine IUPHAR">{{cite web|title=Nicotine: Biological activity|url=http://www.guidetopharmacology.org/GRAC/LigandDisplayForward?tab=biology&ligandId=2585|website=IUPHAR/BPS Guide to Pharmacology|publisher=International Union of Basic and Clinical Pharmacology|accessdate=7 February 2016|quote=K<sub>i</sub>s as follows; α2β4=9900nM [5], α3β2=14nM [1], α3β4=187nM [1], α4β2=1nM [4,6]. Due to the heterogeneity of nACh channels we have not tagged a primary drug target for nicotine, although the α4β2 is reported to be the predominant high affinity subtype in the brain which mediates nicotine addiction [2-3].}}</ref><eod>