KATO III/GFP-luciferase cells are derived from human gastric cancer cell line KATO III by stably integration of a constitutive GFP and Firefly luciferase stably expression construct. KATO III cells are valuable for studying gastric cancer biology, including the mechanisms of tumor growth, metastasis, and response to therapies. KATO III/GFP-luciferase cells stably express GFP and Firefly luciferase, can be used for in vitro assays and in vivo imaging.