TCF7L2 and metabolic syndrome: Other loci, including the melanocortin 4 receptor (MC4R), a key regulator of appetite and energy homeostasis; transcription factor 7-like 2 (TCF7L2), involved in glucose metabolism and β-cell function; and adiponectin gene (ADIPOQ), crucial for anti-inflammatory and insulin-sensitizing activities, further support the strong genetic basis of MetS [37].