ESR1 and cancer: Other known cancer genes residing within substantial aberrant regions defined by Genomic Identification of Significant Targets in Cancer (GISTIC2) included high-level amplifications of MCL1 (44%), AKT3 (21%), GATA3 (19%), E2F3 (18%), NFIB (13%), CCNE1 (12%), IRS2 (12%), PIK3CA (12%), MYB (8%), NOTCH2 (8%), EGFR (5%), FGFR2 (5%) and TERT (4%) and homozygous deletion of RB1 (8%), PTEN (6%), CDKN2A/CDKN2B (5%) and ESR1 (3%).