This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors. Our study reported that miR-31 is a regulator of multiple mRNAs important for different aspects of breast cancer metastasis. We recently identified concerns with several figure panels in which original data were compiled from different replicate experiments in order to assemble the presented figure. The scope of the figure preparation issues includes compiling data from independent experiments to present them as one internally controlled experiment, statistical analyses based on technical replicates that are not reflective of the biological replicates, and comparisons of selectively chosen data points from multiple experiments. As many of the published figures are therefore not appropriate or accurate representations of the original data, we believe that the responsible course of action is to retract the paper. We apologize for any inconvenience we have caused.