MRC5/STAT5 Reporter (GFP) cells are derived from he human fibroblast cell line MRC5 by stably integration of a STAT5 GFP reporter construct. MRC5 cells are widely used in the studies of cell biology, virus biology, cellular aging and toxicology. MRC5/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.