Additionally, an exploratory analysis of the BOLERO3 trial showed greater benefit derived from the addition of everolimus in HER2 positive BC patients with a low PTEN concentration than in those with a high PTEN concentration and in patients with a high pS6 concentration than in those with low pS6 concentration, while again PIK3CA mutations did not seem to predict any benefit [127]. Here, ERBB2 is linked to breast cancer.