Pathways upregulated in breast cancer include glycolysis; metabolic pathways such as pyruvate fatty acid, arginine and proline, and valine, leucine and isoleucine catabolism; protein ubiquitination; RhoA, PI3K/AKT, ILK, 14-3-3-mediated, RAN, aryl hydrocarbon receptor, integrin, clathrin-mediated endocytosis, IGF-1, VEGF, EIF2, actin cytoskeleton, ERK5, GABA receptor, and HER-2 signaling pathways; NRF2-mediated response to oxidative stress; Rho-mediated regulation of actin-based motility; and LPS/IL-1-mediated inhibition of RXR function. The gene discussed is PIK3CA; the disease is breast cancer.