Abstract
A careful molecular biology, epidemiological and mathematical modelling reanalysis of the recently published study titled 'Cancer etiology. Variation in cancer risk among tissues can be explained by the number of stem cell divisions' by Cristian Tomasetti and Bert Vogelstein, which was published on January 2, 2015 in the distinguished journal Science, led to the conclusion that, contrary to the authors' claim, many cancer types are not caused by replicative random mutations. Rather than the authors' two arbitrarily individualized groups of cancer, a three-group model is herein proposed in the framework of this technical comment, considerably reducing the fraction of cancer cases hypothetically attributable to random mutations.