Thus, co-inhibition of either the C-L or T-L sites is usually required to effectively inhibit protein breakdown19,52 and to increase the sensitivity of other types of cancer cells (e.g. solid tumours) to inhibitors of the CT-L site, including BTZ and CFZ53,54; it is nonetheless anticipated that this approach will significantly enhance the toxic effects of the used inhibitors. This evidence concerns the gene CASC3 and cancer.