DKK1-neutralizing antibody reduces primary myeloma burden in SCID-rab mice. (A) Changes in levels of light-chain immunoglobulin (mean ± SEM) from pretreatment in control IgG and anti-DKK1 neutralizing antibody treated hosts. (B-D) Three representative experiments demonstrating heterogeneous response (A, tumor reduction; B, growth delay; C, no response) of anti-DKK1 in SCID-rab mice.