HEK 293/Cre cells are derived from the human immortalized embryonic kidney cell line HEK 293 by stably integration of a constitutive Cre recombinase stably expression construct. HEK 293 cells have been widely used in cell biology research because of their reliable growth and propensity for transfection. HEK 293/Cre cells stably express a nuclear localized Cre recombinase.