Two independent investigators have established the activity of thymoglobulin in multiple myeloma cells from cell lines and patients.38,39 Thymoglobulin has been shown to induce apoptosis via distinct mechanisms in multiple myeloma cells.40 This action appears to be mediated by interactions with surface markers including CD80, CD38, CD40 and CD45. This appears to stimulate apoptosis via cathepsin and caspase pathways.39 By targeting different aspects of the apoptotic process, Thymoglobulin may provide a mechanism to overcome drug resistance in multiple myeloma.