PIK3CA and neoplasm: Functional enrichment of differentially expressed genes (DEGs) in miR-18a/low tumours demonstrated up-regulation of the pathways related to cell motility and migration, ECM activation, pathways related to activation of matrix metalloproteases, Wnt signalling and focal adhesion-PI3K-Akt signalling in TCGA (Figure 2I) and METABRIC series (Figure 2J) (p < 0.05).