However, beyond chemo-sensitization, cell cycle proteins could serve as targets to inhibit metastasis, since delivering specific siRNAs against survivin and cyclin B1 (with linear PEI) were found to be effective to prevent lung metastasis in a mammary adenocarcinoma model in mice (Bonnet et al., 2013). This evidence concerns the gene CCNB1 and breast adenocarcinoma.