TNK2, also named as ACK1, belongs to the protein kinase superfamily and Tyr protein kinase family. It is a non-receptor tyrosine-protein and serine/threonine-protein kinase that is implicated in cell spreading and migration, cell survival, cell growth and proliferation. TNK2 transduces extracellular signals to cytosolic and nuclear effectors. It is a downstream effector of CDC42 which mediates CDC42-dependent cell migration via phosphorylation of BCAR1. TNK2 confers metastatic properties on cancer cells and promotes tumor growth by negatively regulating tumor suppressor such as WWOX and positively regulating pro-survival factors such as AKT1 and AR. The 60-70kd band is the isoform 2 of TNK2. Isoform 1 and 3 is about 120-125kd.