Tiny tumors escape detection via traditional means, but researchers are using a long-wavelength band of light known as the second near-infrared window to penetrate deep into tissue and monitor cancer cells in real time at unprecedented resolution.

This image shows layered nanoparticles (green) illuminating a microscopic tumor. With the ability to selectively target cancer cells now established, researchers are turning their attention to programming the particles to deliver drugs that will annihilate these hard-to-find, early-stage tumors.

Read more about this work here (article published in PNAS, May 2016).