PTP4A1 and breast cancer: These hotspots at or near MCL1 (5.7% samples, 2.7% resulting in MCL1 amplification), PTP4A1 (4.5% samples, 1.25% PTP4A1 amplification) and MYB (6.3%, 1.4% MYB amplification) occurred at lower frequencies than that of common breast cancer amplicons (supplementary Figures S5 and S6 and Note 1, available at Annals of Oncology online for gene expression analysis).