PDPN and neoplasm: Despite a myriad of studies detailing the biological importance of angiogenesis in the tumor setting, the study of tumor lymphangiogenesis has lagged behind until about 2 decades ago, when the identification of lymphatic specific markers such as transcription factor Prox-1 and surface proteins LYVE-1, FLT4 (VEGFR3), and podoplanin accelerated our understanding of lymphatic biology both in the physiologic and pathologic settings [2,6].