METTL1 and digestive system neoplasm: Among them, METTL1, as a methyltransferase, mediates the m7G modification of tRNAs and plays an important role in regulating a variety of biological functions, including yeast growth under heat stress [48], self-renewal and differentiation of embryonic stem cells [30], and even the occurrence of various tumors, including digestive tumors, urological tumors, and hematologic tumors [16, 44, 49–51]; however, its potential role in PTC, including tumor progression and metastasis, is still largely unclear.