Pioneering discoveries from our Laboratory and others have contributed to the establishment of a new modality of chemical intervention into biological system. The new paradigm-shift concept is that of targeting proteins for degradation using small molecules, as an alternative to conventional target blockade or inhibition. Protein degradation can be undertaken by double-headed molecules, also known as PROTACs, that recruit the target for ubiquitin mediated degradation by complexing them with E3 ubiquitin ligases, notably von Hippel-Lindau (VHL) and Cereblon (CRBN), amongst others. We are beginning to understand the rules of how to design and study this new class of molecules in order to trigger efficient, profound and selective downstream protein degradation, and the chemical properties necessary for drug discovery. These allow us to develop molecules that can best allow biological investigation to establish the profound consequences and attractive therapeutic potential of targeting proteins for degradation.