PTEN and neoplasm: The most commonly altered pathway was PI3K/AKT/PTEN, with alterations in one or more of the pathway member genes (PIK3/AKT/PTEN) seen in 62% (98/158) of patients, with no difference in frequency in ER-positive versus ER-negative tumours (p = 0.86) or sequencing performed on archival versus fresh samples (p = 0.229).