Although the tissue structure and cell morphology of MDA-MB-231 xenografts treated with miR-150 inhibitors were not different from those treated with miR-150 inhibitor NC or vector alone, transfection with miR-150 inhibitors significantly reduced the percentage of tumor cells expressing proliferating cell-associated antigen (PCNA) (Figure 4E, Figure S4C). This evidence concerns the gene PCNA and neoplasm.