Somatic copy number alterations (SCNAs) determined by analysis ofhigh-density SNP data identified recurrent focal losses ofCDKN2A and amplifications of CCND1. Wefurther identified low-prevalence cases of focal SCNAs that have been reportedin other cancers, including amplification of CDK4/MDM2 andhomozygous focal deletion of QKI and SAV1(Table S1; FigureS1B). Here, CDK4 is linked to cancer.