It started with the desire to look beautiful. The quest to create medicines on an industrial scale sprang from the chemical industry’s success in dyeing clothes — to look more fashionable, and to represent royalty. By the time World War II broke out, the popular dye industry grew out of manufacturing chemicals only for clothing, to the creation of pharmaceutical products that targeted diseases.

In this new world of medicines, one class of drug easily became dominant: the small molecules. They were molecules that weigh less in terms of molecular weight — under 1,000 dalton to be precise. They became synonymous with synthetic medicines. From the early protagonists of Aspirin and Salvarsan at the start of the 20th century, to the blockbuster medicines of the present time, such as Lipitor or Omeprazole, the chances of you having several small molecule drugs in your cabinet is very high. They have simpler structure, are taken by mouth and have predictable behavior once inside the human body.

The small molecule broke into the cancer scene not so long ago, in 1986. Prior to this, for more than a century, doctors treated cancers with chemotherapy (it is still a big part of cancer treatment). A chemical agent, or few chemical agents used together can kill the most aggressive forms of cancer cells. The principle of using chemo to treat cancer depends on the main character of the cancer cells — they grow rapidly. Chemo killed fast-growing cells and mounted a strong defense against the aggression of cancer cells, treating fire with fire. But some normal cells, which also grow fast, became the spoils of this war between chemo and cancer.

There was room to create more specific treatments, more precise medicines that will target cancer cells only, sparing the normal cells. This requires a feature that will ideally only be present in cancer cells, but not in normal cells — allowing a small molecule to hit the target. But in order to create such a targeted treatment, the scientists needed to figure out the peculiarities of cancer cells — a change, or abnormality not always visible on the outside of the cells, but carry inside of them an unmistakable identity.

We needed to know the molecular markers — the cancer-causing anomaly hidden inside these cells.

At the start of the twenty-first century, a momentous discovery set the tone for the years to come — the sequencing of the human genome. What followed, in my opinion, are the golden years for new cancer treatments. From small molecules with simpler structures, to the cell-secreted antibodies to the poster child of cutting-edge immunotherapy known as cell therapy, the field cancer research is abuzz over a magnificent goal: we shall cure cancers!