The mRNA levels of m6A-related genes, including writers (METTL3 and METTL14), erasers (FTO and ALKBH5), and readers (m6A binding proteins, such as YTHDF1, YTHDF2, and YTHDF3), were assayed by quantitative real-time PCR (qRT-PCR), and the results confirmed that FTO was notably elevated in patients with retinopathy due to type 1 (Figure 1C) and type 2 (Figure 1D) diabetes. This evidence concerns the gene METTL3 and diabetes mellitus.