XPO1 and cancer: Unlike the previously discussed inhibitors, CBS9106 causes a decrease the amount of CRM1 protein in cancer cells, without a compensatory change in the amount of CRM1 mRNA, leading the group to hypothesize that CBS9106 induces CRM1 protein degradation through ubiquitin/proteosome pathway, a hypothesis substantiated by the absence of CRM1 degradation upon the addition of two separate proteosome inhibitors (bortezemib and MG132).