The future of cancer therapies lies in increasingly precise methods of targeting only cancer cells for destruction or reprogramming. Here is another of the many techniques presently under development: "Aptamers are small pieces of RNA that bind to a specific target molecule, usually a protein. They offer ease of use because they can be easily regenerated and modified and therefore have increased stability over some other agents, such as protein-based antibodies. Notably, they have a very low chance of immune-system interference, making them great candidates for tumor diagnosis and therapy. ... Most importantly, it's not necessary to have detailed knowledge of protein changes in the disease before the selection process. This greatly simplifies the process of molecular probe development. The selected aptamers can be used to discover proteins not previously linked with the disease in question, which could speed up the search for effective therapies. ... researchers used a large pool of RNA strands and applied them to a rodent with a liver tumor, the type of metastatic tumor that often results from a colon cancer tumor. ... We hypothesized that the RNA molecules that bind to normal cellular elements would be filtered out, and this happened. In this way, we found the RNA molecules that went specifically to the tumor."