PDPN and esophageal squamous cell carcinoma: Podoplanin (PDPN), a 38-kDa type I transmembrane glycoprotein which is found in some fibroblasts, and an abundance of PDPN-positive fibroblasts is associated with poor prognosis in lung adenocarcinoma, invasive breast cancer, and esophageal squamous cell carcinoma patients[14].