At that point, the tumor cells express pro-angiogenic factors including growth factors such as the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) and enzymes such as cyclooxygenase 2 (COX-2) and protein kinase A (PKA) as well as signaling molecules such as integrins. Here, PTGS2 is linked to neoplasm.