TP53 and Li-Fraumeni syndrome: Importantly, only five out of 11 (45%) TP53 mutation carriers met classic Li Fraumeni syndrome (LFS) or Chompret criteria, or had breast cancer diagnosed under the age of 31.20TP53 mutation carriers also had a significantly higher proportion of HER2+ breast cancer compared to mutation-negative cases (83 vs. 24% in non-carriers, p = 0.004).