In one of these two studies it was noted that there was a marked intra-tumor heterogeneity in translocations, mutations and copy number alterations associated with APOBEC cytidine deaminase activity (thus, driver genes PIK3CA, EP300, TGFBR1, PTPRD and AKAP9 harbored mutations in an APOBEC context), thus providing evidence about a possible functional impact of APOBEC activity on subclonal expansion [88]. This evidence concerns the gene PTPRD and neoplasm.