PIK3CB and neoplasm: Because PTEN-negative tumor cells have been reported to depend more on p110β for oncogenic growth [33, 56], we next assessed how PTEN expression affected clonogenic survival of the PC isogenic pairs, and if PTEN affected sensitivity to small molecule inhibitors of PI3K-p110 and AKT isoforms, or after knockdown of p110/AKT isoforms.