Moreover, to underline the target specific activity of pAXLxCD3ε, a T cell mediated cytotoxic experiment was performed by co-culturing a multiple myeloma (MM) cell line AMO-1, which does not express AXL but express BCMA, (Additional file 2: Fig. S2A) with healthy donor-derived PBMC at 10:1 E:T ratio and treated with pAXLxCD3ε 2.5 μg/ml or increasing concentration of pBMCAxCD3ε ranging from 0.1 to 2.5 μg/ml for 72 h. This evidence concerns the gene AXL and plasma cell myeloma.