MMP9 and schizophrenia: As can be seen in the graphs, most schizophrenia-related genes, including those with trends rather than statistical significance, showed increased expression when patients had horizontal strabismus, which was similar to reports from the biomarker and susceptibility literature in schizophrenia (CTGF, CXCR4, IL7, MMP9, TGFB1, TIMP1, TIMP2, and TNF, Fig. 3A), while NRG1 was decreased in EOMs from patients with strabismus as well as in blood from patients with schizophrenia (Zhang et al., 2008; Wang et al., 2015).