HK2 and neoplasm: Upregulated protein expression level or enzymatic activity of GLUT1, HK2, PFK and PKM2 have been well documented in many human tumour types; in this light, the positron emission tomography (PET) is generally used to detect 18F‐fluorodeoxyglucose (18F‐FDG) uptake for cancer diagnosis in current clinical applications.6