PDPK1 and breast cancer: Previous studies provided evidence that anchorage-independence and xenograft growth of breast cancer cells carrying the activated H1047R PI3KCA allele depended on PDPK1 but not AKT (Gagliardi et al., 2012) and phosphoproteomic analysis of cell lines with activating PI3KCA mutations identified cases in which PDPK1 activity, but not AKT activity, was required for tumorigenicity (Vasudevan et al., 2009).