Effect of PPP in vivo. (A) Serum paraprotein concentrations as determined by serum electrophoresis. (B) Tumor load as determined by flow cytometric analysis. Data are expressed as percentage 5T33MM cells of total cell number. (C-D) Weight of spleen and liver in grams of naive and treated or untreated 5T33MM-bearing mice. (E) Microvessel density. The number of microvessels in the tibiae and femora of the mice, counted by CD31 staining. Mean values ± SD for groups of 10 mice are shown.*P > .05; **P < .001; ***P < .05; ****P < .02.