Given the complex role of the clock in cellular metabolic control and nutritional challenge, and the host of recent publications covering this topic (Guan & Lazar, 2021;Reinke & Asher, 2019;Rijo-Ferreira & Takahashi, 2019;Verlande & Masri, 2019), this review will only cover clock-controlled metabolic alterations in the context of cancer. The gene discussed is CLOCK; the disease is cancer.