Since dysfunction in synaptic activity and cognitive abilities has been recognized as a primary and enduring core deficit in schizophrenia, we examined a set of complement control-related genes as potential susceptibility factors in schizophrenia, and identified statistically strong genetic associations to the homologous genes CSMD1 and CSMD2, as well as to the CR1 locus (C3 receptors) [6]. The gene discussed is CSMD2; the disease is schizophrenia.