Conclusion
Our preclinical studies demonstrated that RNAi therapy against PLK-1 using atelocollagen is effective against liver metastatic NSCLC cancers. Recently, several clinical trials for cancer therapy are ongoing (Additional file 1: Table S1, http://clinicaltrials.gov/ct2/home). Although RNAi shows excellent specificity in gene-silencing, several adverse effects including activation of immune reaction [66,67] and off-target effects (induction of unintended gene silencing) [68] are brought in in vivo application.