The ability to achieve spatial and temporal control over biological processes and drug activation has led to many applications of “photocages”. By definition, photocages are chemical structures that are light-sensitive and is used to “cage” or restrict the activity of any molecule. Upon illumination of light at appropriate wavelength, the protecting group of the molecule is cleaved releasing the active entity. Many recent reports in research areas including molecular biology, neurosciences and drug delivery have demonstrated the applications of photocages. In this write-up, we provide a brief overview on commonly used photocages, ortho-Nitrobenzyl (o-NB) derivatives that are relevant to cancer-biology, and emphasize upon the usefulness and advantages of using these photosensitive molecules.