TK1 and cancer: For example, C-myc mRNA, which exists in a variety of cancers, is particularly important in the development and progression of breast cancer [96]; TK1 mRNA is related to cell division and has been considered a tumor growth marker [97]; GalNAc-transferase mRNA (abbreviated as GalNAc-T mRNA, or GT mRNA) is abundantly expressed in many cancer cells and plays a vital role in the synthesis of gangliosides GM2/GD2 [98,99,100].