Next, we searched for WGCNA modules that showed significantly differential gene expression between SZ neurons and controls. Only one module (pink module with 289 genes) was found (p-value < 0.05) (Fig. 3b). Note that 99 of the 289 genes were in our list of DEGs. PLAU (plasminogen activator, urokinase) and PPP2R1B were the two top hub genes in the pink module (Table 2); both showed increased expression in SZ neurons. PLAU and its receptor (PLAUR/uPAR) are mainly involved in invasion and cell proliferation, and their increased expression is correlated with a wide range of human diseases, including autism, Alzheimer’s, AIDS dementia, cerebral malaria and brain tumors [83]. Their anti-apoptotic effects occur via the caspase-mediated apoptotic pathway and the PI3K/AKT pathway [84]. Markedly elevated levels of uPA/uPAR expression has been reported in chronic neurodegeneration, AIDS dementia complex and other neurological disorders, suggesting that the uPA/uPAR system may contribute to neuronal damage [85, 86]. PPP2R1B encodes a regulatory subunit of protein phosphatase 2 (PP2A), which is involved in the negative control of cell growth and division via the PI3K/AKT pathway [87]. PPP2R1B
