LRP4 and phenylketonuria: In line with our aim to elucidate gene expression patterns in PKU, for the first time, we proposed NT2/D1-derived neurons as a novel model for the Phe-mediated neuronal effect and, also for the first time, pointed out the PREX1, LRP4, CDC42BPG, GPR50, PRMT8, RASGRF2, and CDH6 genes in the context of PKU.