FTO and obesity due to melanocortin 4 receptor deficiency: Like ALKBH5, the primary function of FTO appears to be oxidation of m6A in mRNA, although FTO, the overexpression of which is closely linked to obesity and diabetes,233, 234, 235 also oxidizes the methyl groups of 3‐methylthymine (m3T) and 3‐methyluracil (m3U) in ssDNA.236