As a pan-class I PI3K inhibitor, GDC-0941 shows the same activity (IC50 = 3 nM) against p110α and p110δ enzymes, and in kinase assays, it exerts an inhibitory effect on p110β and p110γ at nanomolar concentrations.196 Experiments have shown that monotherapy or combination therapy with GDC-0941 and other agents has strong antitumor activity in mouse xenograft models of human cancer.196,197. This evidence concerns the gene PIK3CB and cancer.