As an oncogene, PTN is overexpressed in a number of human cancers, and its overexpression contributes to malignant transformation by regulating the expression of a number of genes that participate in multiple aspects of tumorigenesis, such as angiogenesis, cell cycle progression, cell invasion, migration, metastasis and angiogenesis 19, 20, 21, 22. The gene discussed is PTN; the disease is cancer.