After administration /sup 67/Ga concentrates with time in lysosomes from the cytoplasm of liver cells. The lysosomal role in the accumulation of /sup 67/Ga in the liver cell is weakened upon transformation of the liver cell into a malignant tumor cell. In malignant tumors (except for hepatoma) the lysosome does not play a major role in the tumor concentration of /sup 67/Ga. /sup 67/Ga is bound to acid mucopolysaccharides (keratan polysulfate, etc.) in both tumor and liver. In liver cells, large amounts of /sup 67/Ga are transported into lysosomes with these acid mucopolysaccharides, and in hepatoma cells, quite large amounts of /sup 67/Ga are transported into lysosomes with these acid mucopolysaccharides. In malignant tumor cells (except for hepatoma) the effect is much smaller, the acid mucopolysaccharides transporting very little /sup 67/Ga into lysosome. The /sup 67/Ga is concentrated in viable tumor tissue within malignant tissue but hardly at all in necrotic tumor tissue, and concentrates avidly in inflammatory infiltration around tumor cells. Plenty of /sup 67/Ga is found in liver but very little in connective tissue associated with the liver.