CCNE1 and neoplasm: Triple negative (TNBC) and HER2‐positive (HER2+) tumours, conversely, more commonly harbour RB1 loss‐of‐function alterations, altered DNA damage response (DDR), near‐universal loss of TP53 function, CCNE1 and CDK4 amplifications and PTEN loss‐of‐function mutations.5, 6