KTN1 and attention deficit-hyperactivity disorder: In the BG, the GMV of the putamen was most significantly and reliably affected by this set of KTN1 ADHD-risk alleles, consistent with the report that KTN1 was the most significant gene regulating the GMV of putamen [54], and the putamen GMV was the most significant regulator among all brain regions mediating the association between KTN1 and ADHD [83].