TKTL1 and obesity due to melanocortin 4 receptor deficiency: Transketolase-like protein 1 suppression reduces cancer cell proliferation, whereas transketolase activation promotes tumor growth.139 Furthermore, animal studies have shown that chronic fructose feeding causes insulin resistance and obesity.140 A positive relationship was found between fructose consumption and type 2 diabetes and obesity, establishing risk factors for PC.141 However, this association remains inconsistent and requires further investigation.