ERBB2 and breast cancer: miR-21 inhibition caused significant inhibition of tumor growth compared to scramble control in the triple-negative cell line MDA-MB-468 (Figure 1D, p < 0.05), the estrogen-positive MCF-7 line (Figure 1E, p < 0.001) and the Her-2-neu-positive breast cancer cell line SKBR-3 (Figure 1F, p < 0.05).