WHAT WE KNOW
Cancer forms from mutations to DNA, but not just any mutations: The DNA has to mutate in a way that turns off the cell's ability to detect its own mutations, and in a way that allows the cell to keep functioning.
WHAT WE DON'T KNOW
Researchers have identified several genes involved in the mutations leading to cancer, but haven't figured out how to target those genes in a way that stops the cancerous cells from spreading.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.