PIK3CB and adrenal cortex carcinoma: Because PIK75, a potent selective inhibitor of p110α (with weaker affinity to p110γ) isoforms of PI3K, was identified in our qHTS finding as one of the most effective monotherapies against ACC cells, we validated in vitro efficacy of PIK75 and found that PIK75 effectively induced caspase-dependent apoptosis and the G2/M cell cycle arrest in vitro.