Molecular characterization of VQ myeloma cells. (A) Genotyping of Nras^Q61R/+ and Vκ*MYC alleles to assess recombination efficiencies in VQ CD138⁺ cells. (B) hMYC expression in primary CD138⁺ plasma cells was detected using confocal immunofluorescence. Scale bar, 20 μm. The areas within the red rectangles were magnified (×5); original magnification ×60. (C) Quantification of Ki67⁺ cells in primary CD138⁺ cells from moribund VQ MM mice and age-matched control IgG1-Cre, V, and Q mice. (D-E) Quantification of phosphorylated ERK (pERK) (D) and pAKT levels (E) in primary CD138⁺ cells from moribund VQ MM mice and age-matched control IgG1-Cre, V, and Q mice. *P < .05; **P < .01; ***P < .001. DAPI, 4′,6-diamidino-2-phenylindole; Rec., recombined; un-rec., unrecombined.