The TLR7/NF-kB Luciferase Reporter cell line is a stably transfected HEK 293 cell line which expresses full-length human Toll-like receptor 7 (TLR7) and Renilla luciferase reporter gene under the transcriptional control of the NF-kB response element. TLR7 is one of the key innate immune receptors. Functional activity of the cell line has been validated by TLR7 ligand assay, in which upon activation by R848, TLR7 quickly initiates downstream signaling pathway and mediates nuclear translocation of NF-kB (Figure 1).