There is also evidence obtained from a study of the breast cancer signaling pathways, which indicate that EGFR can induce to the ligand-independent and dependent activity of ERα by means of the protein kinase A (PKA) and inhibitor of kappaB kinase α (IKKα) phosphorylation, respectively, thereby closing the positive feedback loop [67, 68]. The gene discussed is ESR1; the disease is breast carcinoma.