For example, the α7 and α4β2 nAChR subtypes, which are expressed at high levels in the brain, are involved in neurological disorders (Alzheimer’s disease, schizophrenia, Parkinson’s disease, attention deficit hyperactivity disorder (ADHD), and inflammation [4,5,6,7,8,9,10]), whereas the α3β4 nAChR is involved in depression and drug addiction [11,12,13]. Here, IGKV2D-24 is linked to attention deficit-hyperactivity disorder.