Studies have also identified differences in mRNA levels of EGR1 in peripheral blood cells (Cattane et al., 2015; Xu et al., 2016; Liu et al., 2017), and one study in fibroblasts (Cattane et al., 2015), of schizophrenia patients compared with controls Interestingly, the differences in EGR1 mRNA levels identified by the two research groups were in opposite directions, which may be due to methodological differences. The gene discussed is EGR1; the disease is schizophrenia.