There was a significant association between OS and PPL mRNA expression, when tumor residual size, grade, stage and age were included in the model, (P = 0.002, HR = 1.3, 95% CI 1.09–1.5, Fig. 4a), suggesting that PPL mRNA expression may be a potential independent prognostic biomarker for OV patients. Here, PPL is linked to neoplasm.