Upregulation of endogenous alternatively spliced tumorigenic variants is frequently observed in many cancers such as the pro-angiogenic splice variant of vascular endothelial growth factor (VEGF165), an EMT-inducing isoform of Rac1 (Rac1b), and the cancer-initiating form of protein kinase C (PKC) betaII [110,111,112,113]. Here, RAC1 is linked to cancer.