Distribution of CDNs among genes. (A) Out of 119 CDN-carrying genes (red bars), 87 have only one CDN. For the rest, TP53 possesses the most CDNs with three others having more than 10 CDNs. (B) CDN number in TP53 among patients. The dark bar represents the observed patient number with corresponding CDNs of the X-axis. The grey bar shows the expected patient distribution. Clearly, TP53 only needs to contribute one CDN to drive tumorigenesis. Hence, TP53 (and other canonical driver genes; see text), while prevalent, does not contribute disproportionately to the tumorigenesis of each patient.