Each cell in the body has a "kill code" embedded in it which acts as a switch that causes infected cells to self-destruct. It's like a natural safety measure that automatically turns off the life of the cell once it senses it is mutating into cancer.
The coded is thought to be embedded in large and small protein-coding ribonucleic acids (RNAs). Scientists deduce the code is a product of evolution, developed more than 800 million years ago as natural protection from cancer. Particularly in small RNAs of microRNAs, the code, when triggered becomes a poison to cancer cells. Recent studies also indicate that chemotherapy also activates these toxic microRNA molecules.
Cancer is unable to adapt, and so is very susceptible, to toxic RNAs. If this so-called kill code can be synthetically produced, toxic RNAs can be a very effective cure for the disease.
Now we can trigger this cancer-defense mechanism without resorting to chemotherapy. We can also avoid risky genome-tampering. We can use these microRNAs, inject them into cells directly and turn the "kill switch" on cancer.
Chemotherapy has plenty of negative side effects. It can even be the cause of secondary cancers because it actually damages and alters the genome.
A Northwestern University paper detailing this "kill code" and how the cancer-ﬁghting microRNAs use the code to kill tumor cells was published October 16, 2018 in eLife.