Their research was centred around the identification of APN/CD13 positivity in primary as well as metastatic tumours using [68Ga]Ga-NOTA-c(NGR) (NOTA-c(NGR)/c[Lys(NOTA)-Asn-Gly-Arg-Glu]-NH2) in experimental rat model systems. The gene discussed is ANPEP; the disease is metastatic neoplasm.