CDK5 and neuroblastoma: In neuroblastoma cells, activation of 5-HT7 receptors induces the formation of filopodia via a Cdc-42-mediated pathway (Kvachnina 2005); in cultured hippocampal neurons, promotes the formation of dendritic spines and accelerates synaptogenesis; moreover, in cultured striatal and cortical neurons, activation of Gα12 leads to pronounced neurite growth via the activation of cyclin-dependent kinase 5 (Cdk5) and ERK (Speranza et al. 2013).