It would be fair to say that the invention of the microscope marked the beginning of modern biology. Later on, the groundbreaking discovery of DNA’s double helix structure established the field of molecular biology. It was hoped that recent successes in analyzing genome sequences would bring about a further leap forward in our exploration of life, but in fact, the mystery has only deepened. In other words, genetic information alone is not sufficient to understand how the proteins produced act and how they are configured. To find out the principles of life itself, we need to actually look at their activity; and to do this, live imaging is essential.