MUC4 expression promotes breast tumor cell aggressiveness. (a) Death of adherent or suspended JIMT-1 cells stably transduced with scrambled or MUC4-directed shRNA was measured by sub-G1 DNA content. The fold increase in the probability that the cells will undergo death in the absence of MUC4 relative to MUC4 expression was calculated and plotted for adherent and suspended conditions. 1 represents no effect, and 5 represents a 5-fold higher probability as calculated by odds ratio, with a P value of < 0.001. Error bars indicate the 95% confidence interval for the population, and the points indicate the center of the confidence interval. (b) JIMT-1 cells described in (a) were analyzed for DNA content by fluorescent-activated cell sorting, and the percentage of cells outside G1 phase of the cell cycle (excluding sub-G1) were plotted. (c) Migration of JIMT-1 cells stably transduced with scrambled and MUC4-directed shRNAs was determined by Boyden chamber assay. * P < 0.05.