Genome-wide association studies show thatpolymorphic variants in TCF4, predominantly localized innon-coding regions of the gene, are associated with variouspsychiatric disorders, including schizophrenia (Stefansson etal., 2009; Ripke et al., 2011; Steinberg et al., 2011; Smoller etal., 2013; Bocharova et al., 2017), bipolar disorder and autismspectrum disorders (Smoller et al., 2013), major depressivedisorder (Wray et al., 2018), and post-traumatic stress disorder(Gelernter et al., 2019). The gene discussed is TCF4; the disease is schizophrenia.