A promising solution rests at the intersection of engineering and biology: microfluidics. Using tiny customized remixes of the classic biological petri dish, researchers can simulate conditions found in a body and control for specific variables such as enzyme changes or the presence of growth factors. In much the same way that NASA used simulations on Mars to successfully model and actually land the Curiosity Rover, researchers are beginning to replicate in vivo and in vitro scenarios to study anomalies including the growth and spread of tumors.