CD138^low/neg MM cells upregulate JAM-C in murine BM. (A) Flow cytometry of living eGFP⁺ MM cells in murine BM defines CD138^high and CD138^low/neg MM cells; the latter show significantly elevated JAM-C expression. The horizontal lines represent the mean MFI. (B) Statistical analyses of MM cells in BM regarding CD138 and JAM-C expression (percentages of GFP⁺ cells). JAM-C expressing (mean fluorescent intensity [MFI]) BM and PB cells gated on living and GFP⁺ cells divided into CD138^high and CD138^low/neg cells of MM mice (n = 6) at day 21 after MM cell injection. Unpaired, two-tailed Student t tests were used. Error bars indicate SD.