CDKN2A and neoplasm: Additionally, in a second set of DNA copy number profiles of 2476 tumor specimens from 39 tumor types (Tumorscape24), we observed deletion limitation in the CDKN2A, MAP2K4, and PTEN regions (Supplementary Fig. 6a–g) whereas the results were inconclusive in the other four regions, most likely because the latter data set was generated using lower-resolution microarrays (Affymetrix 250k) and lower-purity samples (median tumor cell fraction 58% compared to 89% and 99% for TCGA and CCLE; Supplementary Fig. 3), making it harder to detect homozygous deletions.