A549/STAT3 Reporter (Luc) cells are derived from the human A549 lung carcinoma cell line by stably integration of a STAT3 firefly luciferase reporter construct. A549 cell line has been widely used in cancer research, immunological studies and drug development. A549/STAT3 Reporter (Luc) cells stably express firefly luciferase under the control of the STAT3 response elements, can be used for monitoring the activity of STAT3 signaling pathway.