Thus, we examined the forebrain mRNA expression of genes that are known to be important for neuronal migration and layer formation, such as brain-derived neurotrophic factor (BDNF), neurotrophic tyrosine kinase receptor type 2 (TrkB), Reelin, cyclin-dependent kinase 5 (Cdk5), and disrupted in schizophrenia 1 (DISC1), and the neocortical layer II/III laminar-specific genes, such as transducin-like enhancer of split 3, homolog of Drosophila E (Tle3), kit ligand (Kitl), LIM homeobox protein 2 (Lhx2), cut-like homeobox 2 (Cux2), and SLIT and NTRK-like family, member 1 (Slitrk1) (Figure 2). This evidence concerns the gene CDK5 and schizophrenia.