PROX1 and squamous cell lung carcinoma: It is well established that down-regulation of PROX1 reduces the proliferation of colorectal, cervical cancer, oral, esophageal cancer cells and lung squamous-cell carcinoma cells whereas it significantly promotes the growth of hepatocellular carcinoma cells in vitro and does not significantly influence the proliferation rate of EOMA and Py-4-1 cells or renal cancer cells [28, 30-32, 45, 46, 48, 49, 54-56].