As shown in Supplementary Fig. 4A–B, DTP3 administration by this dosing schedule induced a strong pharmacodynamic response, denoting therapeutic target engagement, in virtually all CD138+ cells within tumours, as shown by the near-complete shift in the signals reporting JNK phosphorylation and caspase-3 cleavage, and the marked increase in the percentage of MM cells exhibiting a sub-G1 DNA content, a hallmark of apoptosis. Here, SDC1 is linked to neoplasm.