The ALK (2p23.2) Break Apart FISH Probe is designed to detect the rearrangement of the ALK gene located on 2p23. The ALK gene can fuse with one of 20 known ALK gene rearrangement partners, the most common being t(2;5)(p23;q35)1.The resultant fusion proteins generated from ALK gene rearrangement plays a vital role in driving the pathogenesis of several different types of cancer, such as nonsmall lung cancer and anaplastic large cell lymphoma2.