RAC1 and neoplasm: While long-term downregulation of RAC1 and CFL2 mRNA levels by miR-142-3p in patient tumor tissues may be of relevance for metastatic spread, it cannot serve as an explanation for our in vitro observations, as a downregulation at the protein level was not observed due to a high protein stability, or low turnover rates, respectively (K. Brüggemann, unpublished).