HK2 and head and neck squamous cell carcinoma: In addition, HK2 is connected to poor prognosis (Table 1) in colorectal cancer [54], glioblastoma multiforme [55], pancreatic cancer [56], cervical squamous cell carcinoma [39,57], prostate cancer [58], head and neck squamous cell carcinoma [59], HCC [45] and other tumor types [3], and two independent meta-analyses in tumors of the digestive system indicate HK2 as a negative prognostic marker associated with shorter overall survival and progression free survival [60,61].