PTK2 and neoplasm: What is more important, it is reported that Capn4 is involved in tumor progression through many pathways, such as epithelial-mesenchymal transition (EMT), the FAK–Src signaling pathways, the Wnt/β-catenin (β-catenin), and the nuclear factor κB (NF-κB) signaling pathways [24, 30–32].