Fig. 1. Distribution of chromosome number in common cancers. The percentage of tumors plotted against the corresponding maximum chromosome number reveals that diploid or near-diploid karyotypes dominate across cancer types. A high percentage of tumors with near-triploid or near-tetraploid chromosome numbers suggests that changes in whole chromosome sets are frequent in cancers. The Mitelman Database of Chromosome Aberrations in Cancers was used as a source of the data (http://cgap.nci.nih.gov/Chromosomes/Mitelman). The bracketed numbers indicate the number of tumors analyzed for each cancer.