NRXN1 and schizophrenia: Among important works on CNVs, a large genome-wide study by the CNV Working Groups of PGC analyzing 21,094 schizophrenia cases and 20,227 controls [31] identified copy number losses at six loci (1q21.1, 2p16.3 involving NRXN1, 3q29, 15q13.3, distal 16p11.2, and 22q11.2) and gains at two loci (7q11.23 and proximal 16p11.2) that are significantly (P < 1.33 × 10−4 for losses and 4.33 × 10−5 for gains) associated with schizophrenia after multiple testing corrections (Table 1c).