PIK3CA and cancer: NF1 acts as a tumor suppressor through inactivating Ras activity; therefore, when NF1 is mutated, Ras-related signal pathways, e.g., MEK–ERK, and PI3K-AKT pathways, are hyperactivated, which results in poor clinical outcomes for cancer patients (Malone et al., 2014; Redig et al., 2016).