GPC1 and schizophrenia: Potkin et al. [14] carried out a genome-wide study on schizophrenia by using QTs with results showing that variants in six genes (POU3F2, TRAF, GPC1, POU3F2, TRAF, and GPC1) were associated significantly with working memory task-related bold signal of functional MRI in schizophrenia, with a p-value threshold of 10−6.