Jeko-1/GFP cells are derived from the human precursor B cell lymphoblast cell line Jeko-1 by stably integration of a constitutive GFP stably expression construct. Jeko-1 cells stably express CD19, are ideal for testing CAR T cell or other immunotherapies. Jeko-1/GFP cells stably stably express GFP, can be used for in vitro assays and in vivo imaging.