TK6/STAT5 Reporter (Luc) cells are derived from the human lymphoblastoid TK6 cell line by stably integration of a STAT5 firefly luciferase reporter construct. TK6 cells are heterozygous for thymidine kinase (TK), are commonly used in research related to genotoxicity, mutagenesis, and DNA repair, as well as evaluating the safety of new drug candidates. TK6/STAT5 Reporter (Luc) cells stably express firefly luciferase under the control of the STAT5 response elements, can be used for monitoring the activity of STAT5 signaling pathway.