PTP4A3 and melanoma: Finally, high PTP4A3 expression has been linked to increased tumor aggressiveness in different types of solid tumors, e.g., melanoma, gastric cancer, colon cancer, hepatocellular carcinoma and breast cancer [20], [21], [22], [23], [24], possibly because high PTP4A3 expression leads to increased epithelial-mesenchymal transition [25].