This book takes you on a journey to the basic concepts of Cancer Biology. We combine developmental, evolutionary and cell biology perspectives, to then wrap-up with an integrated clinical approach in the form of case studies, where molecular diagnosis as well as various classical and modern therapeutic strategies will be addressed. We look at cancer cells as outlaws, i.e. Cells that break the rules żeby which the multicellular society is generated and maintained; cells that not only disrupt their self-control buttons but can also hijack and "corrupt" their host to help them thrive.The book starts with an Introductory Chapter where the different themes tackled later are framed within a developmental and evolutionary perspective - like looking at Cancer in a nut shell. Then, in each subsequent specific Chapter, we go deep. We first explore the idea of cancer as a mass of somatic cells undergoing a micro-evolutionary Darwinian process. Then, go through the main Hanahan and Weinberg "Hallmarks of Cancer", revising the topics of signaling, proliferation, apoptosis, genomic instability, DNA damage, cancer metabolism and further into the hallmarks that illustrate how cancer cells hijack the host. Tumor cells not only escape immune detection but also subvert and corrupt immune cells to work for them - turning them into bad cops.... Another form of takeover of the host is when tumor cells recruit blood vessels to feed the tumor and help them invade and migrate to distant sites forming metastasis. In most Chapters, we try highlight fundamental experiments that led to key concepts, connecting basic biology and biomedicine. In the book's closing section all of these concepts are integrated in clinical studies, where molecular diagnosis as well as the various classical and modern therapeutic strategies are addressed.We tried to write this book with an easy-to-read language, like a one-on-one conversation between the writer and the reader, without in any instance compromising scientific accuracy and rigor. Therefore, we believe this book is suited not only for advanced undergraduates and master students but also for patients or curious lay people looking for a further understanding of this shattering disease.