PLK2 and head and neck squamous cell carcinoma: Phosphorylation of p53 family member TAp73 at Ser48 restricts its nuclear translocation and anti-tumor effects, which could be reactivated by dephosphorylation; Contrasting to cisplatin alone, combination therapy with PLK2 inhibitor (ELN582646) upregulates p21 and puma expression in head and neck squamous cell carcinoma and OS cell line (117, 118); Inhibiting PLK2 in TAp73-rich OS cell line Saos2 leads to reduced cell proliferation, increased apoptosis, and decreased invasion; However, these changes are not observed in TAp73 KO Saos2 (119, 120).