PIK3C2A and schizophrenia: EIF2AK2 had the most significant gene-based score in the chromosome 2p22 region, whereas the neighboring gene to RPS13, PIK3C2A, is more significantly associated with schizophrenia (P=0.000126) than RPS13, thus not allowing us to verify the specific source of the RPS13 association signal from this analysis (data not shown).