PIK3CA and breast cancer: Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the upregulated genes revealed significant enrichment in metastasis-related pathways, including Wnt signaling pathway, as well as ECM-receptor interaction, PI3K-Akt signaling, TGF-beta signaling, Rap1 signaling, Hippo signaling, breast cancer pathway, MAPK signaling, focal adhesion, Ras signaling, and PPAR signaling pathways (Figure 4A).