Raji/STAT5 Reporter (GFP) cells are derived from the human Raji B lymphoblastoid cell line by stably integration of a STAT5 GFP reporter construct. Raji cell line was generated from human Brukitt's lymphoma. Raji cells express CD19, making them a useful model for studying CD19-related signaling and therapies. Raji cells are used to assess the effectiveness of CAR T cells engineered to target CD19, and serve as a model to test CD19-targeting antibodies for potential therapeutic applications. Raji/STAT5 Reporter (GFP) cells stably express GFP under the control of the STAT5 response elements, can be used for monitoring the activity of STAT5 signaling pathway.