HK1 and head and neck squamous cell carcinoma: Hypoxic conditions upregulate HK1 (hexokinase 1), a critical glycolytic enzyme (Cheng et al., 2018), which has been linked to poor prognosis in malignant melanoma, head and neck squamous cell carcinoma, and oral squamous cell carcinoma (Zhou et al., 2019; Han et al., 2021).