FTO and obesity due to melanocortin 4 receptor deficiency: It is known that FTO, as an obesity-related protein, can catalyze the demethylation of m6A. Numerous studies have indicated that FTO is significantly upregulated in various cancerous tissues, including but not limited to cervical squamous cell carcinoma (79), lung squamous cell carcinoma (80), gastric cancer (81) and pancreatic cancer (82).