PIK3CA and prostate cancer: Driven by the hypothesis that PTEN-binding miRNAs may regulate this signaling pathway, we report for the first time that the four miRNAs, including miR-19b, miR-92a, miR-23b and miR-26a, promote prostate cancer cell proliferation by regulating the expression of PTEN and its downstream signals, PI3K/Akt and cyclin D1.