U937/NF-kB Reporter (Luc) cells are derived from the human pro-monocytic cell line U937 by stably integration of a NF-kB firefly luciferase reporter construct. U937 cells are able to differentiate into either dendritic cells or macrophages, depending on the surrounding signals. U937 cells are widely used for studies of monocyte/macrophage differentiation, the macrophage-tumor cell interaction and anti-cancer drug screening. U937/NF-kB Reporter (Luc) cells stably express firefly luciferase under the control of the NF-kB response elements, can be used for monitoring the activity of NF-kB signaling pathway.