This ''chromosomal chaos'' [600] or ''cancer as a chromosomal disease'' perspective is viewed by some researchers not as just a side consequence of mutational damage, but as the main core theme to understand a number of unexplained issues in cancer progression. ''In sum, cancer is caused by chromosomal disorganization, which increases karyotypic entropy'' [601] . Regarding the cancer types studied in this paper, one particular ''measure of disorder of a system'', aneuploidy, has been observed in poorly-differentiated prostate cancer cells and it is often associated with a more agreessive phenotype [602, 603] , increased PSA levels [604, 605] , and correlate with Gleason score [606, 607, 608] . Gene fusions and chromosomal rearrangements are other source of increase in the ''disorder'' of the genome organization and they are increasingly being recognized as a major player in prostate cancer progression [609] . The increase in ''karyotypic complexity'' and ''extended aneuploidy and heteroploidy'' may be already enough to develop a malignant melanoma phenotype, as the report of Gagos et al. indicate [610] . The observed finding of aneuploidy in melanoma (also including uveal melanoma) is also increasingly important due to a number of different independent observations [247, 611, 612, 613, 614, 615, 616, 617, 618] . It is in this context that the word 'entropy' has been used.