Figure 4. Normal and MM BM-MSC–derived exosomes differentially affect MM cell homing and growth in vivo.

Detection of MM cell homing to the BM was performed by in vivo confocal microscopy (original magnification, ×5). Green, GFP⁺ MM cells (denoted by arrows); red, Evans Blue–positive blood vessels. Specific BM niches are shown in boxed regions with dotted lines; relative tridimensional reconstruction is shown for each panel (scale expressed in μm). In B, specific BM niches were obtained by changing the focal plane, moving toward the skull of the mouse (boxed region with solid line).