CCND1 and head and neck squamous cell carcinoma: For example, in the cytoplasm, abnormal tRNA modifications mainly mediate the translation of oncogenes, for example, Methyltransferase 1/WD Repeat Domain 4 (METTL1/WDR4)-mediated m7G tRNA modifications can enhance the translation of CyclinD1, a recognized proto-oncogene, in head and neck squamous cell carcinoma, and CyclinD1 overexpression can lead to uncontrolled cell proliferation [35].