Meanwhile, exogenous miR-186-5p mimic in MDA-MB-231 cells significantly inhibited the expression of SBEM, p-PI3K, p-AKT and their downstream pathways, MMP1, MMP3, MMP9, CyclinD1, PCNA and CyclinB1 proteins and reduced proliferation of breast cancer cells. The gene discussed is PCNA; the disease is breast cancer.