The activation of Hippo signal pathway via overexpressing MST1 or down‐regulating YAP could inhibit cell proliferation while promote cell cycle arrest and apoptosis via regulating survival‐related signals by YAP‐TEAD complex in NKTCL cells, indicating that Hippo signaling pathway played a critical role in the tumorigenesis of NKTCL. The gene discussed is MST1; the disease is extranodal nasal NK/T cell lymphoma.