PDPN and esophageal cancer: Human podoplanin (hPDPN) is expressed in many cancers, including malignant gliomas, lung cancers, esophageal cancers, malignant mesotheliomas, testicular cancers, bladder cancers, and osteosarcomas 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and the expression of hPDPN in cancer‐associated fibroblasts contributes to poor prognosis 14, 15, 16, 17, 18, 19.