Since Halberg's conception of cancer chronotherapy, a tremendous effort has been made within the scientific community to understand the basic biological underpinning of circadian‐based medicine, ultimately culminating in the 2017 Nobel prize in physiology and medicine being awarded to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their work in elucidating the molecular mechanism of the circadian clock. Here, CLOCK is linked to cancer.