Parvalbumin+ cells innervate multiple pyramidal cells and contain lower mRNA for parvalbumin and GAD67 in those with schizophrenia (124) and reduced expression of the potassium channel KCNS3 gene which encodes the Kv9.3 potassium channel α subunit and is essential for control over its fast-spiking abilities (197). Here, PVALB is linked to schizophrenia.