CDKN2A and neoplasm: Yet, this group (35% of MIBC in the TCGA cohort), also comprises 41% of tumors with CDKN2A deep deletions, meaning that CDKN2Ahigh tumours, which do not show any homozygous deletion of CDKN2A, are in part not a representative, but a highly selected subgroup of basal squamous tumours.