SERPINE1 and neoplasm: This experiment also showed a dose-dependent inhibitory effect of PER on cell viability and that the combination of PER and the SERPINE1 inhibitor tiplaxtinin (as tumor SERPINE1 overexpression may be related to poor prognosis) demonstrated further reduced cell viability in PER-resistant U-138MG cells, which have high expression levels of SERPINE1 (54).