Cancer - A devastating disease, but also an eye-opener and window into the deep mysteries of life and its origins.

Although cancer is still the second leading cause of death worldwide, basic research has largely elucidated the underlying mechanisms that lead us deep into the laws of animate and inanimate nature. This review aims to demonstrate that the cancer process profoundly affects and reprograms fundamental principles and concepts of cellular life by harnessing the natural mechanisms of biological evolution. It is shown that mutation and selection - the drivers of cancer formation and progression - are mandatory consequences of Boltzmann's version of the second law of thermodynamics, which stipulates that entropy (or disorder) according to probability never decreases, followed by Darwinian evolution by filtering for the suitable geno- and karyotypes. Cancer research has shown that malignant cells can develop gradually or abruptly depending on the prevailing stress conditions. Similar principles were then observed in the evolution of species, referred to as micro- and macroevolution. Cancer cells can be related to phylogenetically older forms of life, and malignant transformation can be viewed as reverse (atavistic) evolution, accompanied by typical rearrangement of system information and loss of 'social' behavior. It becomes obvious that in nature no distinction is made between normal biology and pathobiology. Instead, everything follows the rules of natural evolution. This illustrates the depth of the cancer problem and may explain the serious difficulties faced in trying to eradicate cancer.