Initial in vivo studies of radionuclide conjugates of GSAO demonstrated that 111In conjugated to GSAO with diethylene triamine pentaacetic acid (DTPA) non-invasively imaged tumour cell death concordant with 99mTc-labelled annexin V with relatively lower levels of uptake in normal tissues and organs except for the kidneys [10]. This evidence concerns the gene ANXA5 and neoplasm.