In PIK3CA mutant breast cancer cells, PDK1-SGK1 signaling has been shown to sustain AKT-independent mTORC1 activation to promote resistance to the p110α-isoform-specific PI3K inhibitor BLY719, and PDK1 or SGK1 blockade can restore BYL719 sensitivity [145]. The gene discussed is PIK3CB; the disease is breast carcinoma.