Notably, we found that the overexpression of CYP4Z1- or CYP4Z2P-3′UTR rescued the six2 knockdown-mediated inhibition of breast cancer cell stemness, characterized by increasing cell spheroid formation (Additional file 13: Figure S7A and S7B), CD44+/CD24− population (Additional file 13: Figure S7C), and expression of stemness markers and reactivation of the PI3K/Akt and ERK1/2 signaling (Additional file 13: Figure S7D–G). This evidence concerns the gene PIK3CA and breast cancer.