In other oncological applications,tumor cells have been radiolabeledto study metastasis in preclinical models, examining for example therole of protein kinase C (PKC) or surface sialylation in the accumulationof metastatic cells in the liver383,384 or the tropismof different tumor cell lines to the liver and lungs.385 However, tumor metastasis is generally a slowerprocess than the radioactive decay of the most commonly used radionuclidesfor cell labeling. The gene discussed is PRRT2; the disease is neoplasm.