Podn, also known as podocan, is a small leucine-rich repeat protein. It is involved in multiple biological processes. It has been linked to the regulation of smooth muscle and tumor proliferation, potentially through signaling pathways such as Wnt/β-catenin, TGF-β, and Akt/mTOR [3]. It is also related to various diseases, including osteosarcoma, glioma, and stomach cancer [3].

In osteosarcoma, PODN has shown promise as a prognostic biomarker. Integrated bioinformatics analysis identified it among differentially expressed genes, with its expression having a good diagnostic value (AUC value of 0.855) [1]. Hypermethylated PODN was found to repress osteosarcoma progression by inactivating the TGF-β/Smad2/3 pathway, as overexpression of PODN prevented OS cell proliferation, migration, invasion, and inhibited tumorigenesis in xenograft mice [2]. In human bladder smooth muscle cells, miR-3180-5p, which is upregulated under hydrodynamic pressure, promotes cell proliferation by inhibiting PODN expression via the cdk2 signaling pathway [4].

In summary, PODN plays a crucial role in regulating smooth muscle and tumor-related biological processes. In osteosarcoma, it serves as a potential biomarker and its hypermethylation-mediated inactivation of the TGF-β/Smad2/3 pathway has important implications for understanding and treating this disease. Research on PODN provides valuable insights into the mechanisms of related diseases and may offer new strategies for diagnosis and treatment.