In addition, the signaling pathway associated with angiogenic action of 5-HT is known to be mediated by a mechanism similar to that associated with the angiogenic effect of vascular endothelial growth factor (VEGF) (e.g., via the activation of PI3K/Akt signaling) [29], which suggests potential overlap between signaling molecules with respect to cancer proliferation/invasion and angiogenesis. This evidence concerns the gene AKT1 and cancer.