NSUN4 and colorectal carcinoma: The expression levels of most of the m5C writers (NOP2, NSUN2, NSUN4, NSUN5, NSUN6, NSUN7, DNMT1, DNMT3A, and DNMT3B) and readers (YTHDF2, ALYREF, and YBX1) were significantly upregulated in the CRC tissues compared to those in the normal tissues, whereas the expression of the m5C eraser TET2 was downregulated in human CRC tissues (Figure 2A; Supplementary Table 1).