The tropomyosin receptor kinases (TRK) are a family of tyrosine receptor kinases, which include TrkA, TrkB and TrkC. TrkA is activated by binding to nerve growth factor (NGF), resulting in activation of cell proliferation through the RAS/MAPK/ERK and PLCγ/PI3K pathways. Constitutive activation of TrkA is associated with colorectal cancer, suggesting TrkA inhibitors may have potential therapeutic value. The TrkA Assay Kit is designed to measure TrkA activity for screening and profiling applications using Kinase-Glo® MAX as a detection reagent.