PLK1 and extranodal nasal NK/T cell lymphoma: It has been proved that PLK1 is activated in the G2 phase by phosphorylation of T210 residues in its T-ring before entering Mitosis [12], although the abnormal activation of PLK1 plays an important role in the occurrence and development of various lymphohematopoietic and immune-related tumors, the expression and mechanism of PLK1 and its phosphorylation levels in NKTCL, as well as their relationship with clinical pathological characteristics and prognosis of NKTCL, have not been reported yet.