Pharmacogenomic investigations comparing GEP data obtained at baseline and 48hr post-treatment have been performed in case of thalidomide, dexamethasone, lenalidomide, bortezomib and melphalan3. Thus, as most patients on TT3 had baseline and 48-hr GEP investigations performed after bortezomib, the opportunity exists to investigate, at the time of relapse, not only a re-challenge with bortezomib with 48hr GEP but also pomalidomide's effect.