Furthermore, clinical studies with different tracers are being conducted to extend the use of nuclear imaging to gaining insight into the different aspects of tumour physiology, such as proliferation (e.g. 18F-fluorothymidine (FLT-PET) 71-73), hypoxia (e.g. 18F-fluoromisonidazole (F-MISO)-PET 55, 74, 75) and angiogenesis (e.g. with radiolabelled arginine-glycine-aspartic acid (RGD) peptide tracers 76 or vascular endothelial growth factor expression 76, 77). Here, VEGFA is linked to neoplasm.