Tumorigenic potential of SP and MP cells. (A) CB17/SCID mice were subcutaneously inoculated with SP or MP cells from KMS11 cell line at 0.25 × 10⁶, 0.5 × 10⁶, and 10⁶ cells/mouse. (B) CB17/SCID mice were inoculated with SP or MP cells from KMS11 cell line at lower numbers 1 × 10³, 10 × 10³, and 100 × 10³ cells/mouse. (C) CB17/SCID mice were subcutaneously inoculated with SP or MP cells from OPM1 cell line at 0.25 × 10⁶, 0.5 × 10⁶, and 10⁶ cells/mouse. (D) NOD/SCID mice were subcutaneously inoculated with SP and compared with MP cells from KMS11 cell line at 500 × 10³, 250 × 10³, 100 × 10³, 10 × 10³, and 1 × 10³ cells/mouse. Caliper measurements of tumor diameters were done every 5 days. Representative pictures were performed using camera IVIS 1327 in the Xenogen system.