PIK3CD and breast cancer: The dysregulation of the PI3K/AKT signaling pathway occurs frequently in human cancers, often attributed to RTKs and somatic mutations in specific components of this signaling pathway.[76] Approximately 30% to 40% of cases exhibit mutations in PIK3CA in breast cancers, which induces overactivation of the α isoform of PI110K (p3α),[5] and aberrant stimulation of the PI3K/AKT pathway has been linked in tumor growth, angiogenesis, and survival[35] and is also implicated in resistance to EGFR-mediated endocrine therapy and other forms of directed therapy, such as targeting HER2 resistance.[77,78]