(iv) Patients with high-risk HNSCC (HPVneg, mutant TP53) whose tumors resisted post-operative RT (51) show evidence of pathway activation, whereby elevated PIN1 expression levels strongly associate with locoregional recurrence (LRR; P = 0.006) and reduced overall survival (OS; P = 0.007) (47). Here, PIN1 is linked to head and neck squamous cell carcinoma.