PODNL1, a member of the small leucine-rich proteoglycans family, has been identified to be closely associated with the prognosis of ovarian cancer and glioma. In this study, we explored the role of PODNL1 in the progression of bladder cancer (BLCA). TCGA data analysis showed that the expression level of PODNL1 in BLCA tissues was significantly higher than that in adjacent tissues. The high expression of PODNL1 was related to T stage, N stage, pathological stage, pathological grade and histo-logical type of BLCA. The results of qPCR further confirmed that the expression of PODNL1 in BLCA cell lines was significantly higher than that in normal bladder epithelial cells (SV-HUC-1). In addition, PODNL1 knockdown decreased the proliferation and migration abilities of BLCA cells, while PODNL1 overexpression promoted the proliferation and migration abilities of BLCA cells. WGCNA and functional enrichment analysis showed that PODNL1 expression was closely related to the epithelial mesenchymal transformation (EMT) pathway of BLCA. Furthermore, GSCA database analysis also showed that high expression of PODNL1 activated the EMT pathway of BLCA. The results of qPCR indicated that PODNL1 gene expression level was negatively correlated with e-cadherin expression, and positively correlated with N-cadherin expression. Thus, these results suggest that PODNL1 regulates EMT process. Addition-ally, high expression of PODNL1 was closely associated with poor prognosis in BLCA patients. In conclusion, PODNL1 is a potential therapeutic target and prognostic biomarker of BLCA.(c) 2022 Elsevier Inc. All rights reserved.