RAPGEF2 and schizophrenia: Recent data implicating the Rapgef2 gene locus in schizophrenia, as one of only nine copy number variations segregating to all genotyped affected members within several families with schizophrenia (Xu et al., 2009), and our own work implicating Rapgef2 in neuroendocrine control of ERK activation, a key component in cellular processes underlying learning and memory (Morozov et al., 2003), impelled a detailed investigation of the role of Rapgef2 in ERK neuronal signaling in the adult brain.