Introduction to Cancer Biology is a short primer on how cancers develop and grow. The aim of this book is to provide a gentle exploration of the fundamental concepts in a easy-to-understand format, using examples and key figures for illustration. It is written in a style to help the reader understand the six basic principles that inform our current understanding of cancer, at the molecular, cellular and physiological level. The text can be used either as a first step towards a deeper understanding of the mechanisms of cancer progression or it can be used as a quick revision guide. It would be suitable for anyone, with or without a background in biology.