The search terms included “insulin resistance and cancer,” “hyperinsulinemia,” “IGF system,” “diabetes and cancer,” “obesity and cancer,” “inflammation,” “metformin,” “mitochondrial dysfunction,” and “Warburg effect,” in combination with specific cancer types such as “breast,” “colorectal,” “pancreatic,” “liver,” and “endometrial.” Foundational experimental studies, large epidemiological cohorts, meta-analyses, and clinical trials were prioritized for inclusion to provide a comprehensive overview of the topic. The gene discussed is IGF1; the disease is hyperinsulinism.