TP53 and breast cancer: VX‐680‐induced apoptosis and endoreduplication readily increases in p53‐dysfunctional cells than in p53 wild‐type A549 or HCT116 cells.70, 71 The sensitivity of breast cancer cells to AMG900 also correlates with p53 loss‐of‐function mutations and low expression of p21.18 This suggests that pan‐Aurora inhibitor‐induced apoptosis is mediated via a p53‐independent pathway.