Meet Monsieur Valentin! It is the kidney, the most important organ in the human body. “I am the true essence of extraordinary ability. 24/7 I provide waste removal, blood stability, blood pressure control, red blood cell production, vitamin D activation, and bone calcium! You need to take care of my health: if I don’t exist, there won’t be any life!” This non-fiction book is written with humor and features funny illustrations, but is intended for adult readers who want to learn more about how their bodies work and how to stay healthy for many years to come. And the story of Valentin’s modest kidney was told by the leading French nephrologist, professor, head of the nephrology department at the Pitié-Salpêtrière Hospital (Paris), Dr. Gilbert Deray.