Molecular epidemiological studies have demonstrated that polymorphisms in circadian genes are associated with the risk of a number of types of cancer, such as breast, ovarian, prostate cancer, and non‐Hodgkin lymphoma.10, 11, 33, 34, 35, 36 CLOCK‐BMAL1 heterodimer is at the heart of the molecular circadian autoregulatory feedback loop. Here, CLOCK is linked to cancer.