PIK3CA and breast cancer: In order to further support the functional roles of miR-564 target genes in PI3K and MAPK pathways and G1/S transition by using breast cancer patient data, we have analyzed the correlation between mRNA expression of miR-564 targets and the expression/phosphorylation of PI3K and MAPK pathways and cell cycle proteins by using the Cancer Genome Atlas (TCGA) data43.