Effects of preventative administration of the anti-α4 Ab on apoptosis of 5TGM1/luc myeloma cells in bone. Apoptotic 5TGM1/luc myeloma cells with characteristic morphology including cell shrinkage, nuclear pyknosis, and chromatin condensation were counted on H-E-stained histological sections as described in “Materials and methods.” Data are mean ± SEM (n = 5). ^*Significantly different from untreated group.