TT/STAT3 Reporter (Luc) cells are derived from the human medullary thyroid carcinoma (MTC) TT cell line by stably integration of a STAT3 firefly luciferase reporter construct. TT cells have been widely used for medullary thyroid carcinoma (MTC) research, particularly in studies related to calcitonin production, tumorigenesis, and the development of targeted therapies. Its ability to secrete calcitonin and form tumors in vivo makes it a valuable model for both in vitro and in vivo studies of MTC biology and treatment. TT/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.