SERPINE1 and glioma: Furthermore, the levels of PAI-1 in patient-derived glioma cell supernatants as compared to U2987MG were verified by using ELISA in both Proneural (U3016MG, U3047MG, U3117MG) and Mesenchymal (U3065MG, U3060MG, U3062MG, U3101MG) subtypes with previously identified low (U3016MG, U3047MG, U3065MG) and high (U3117MG, U3101MG, U3060MG, U3062MG) mRNA level of PAI-1 (Figure 2B).