In contrast, the tumor sizes in the SCID-rab mice inoculated with myeloma cells stably expressing the PF4 gene was significantly smaller (102.3 ± 19.8 mm3, 118.2 ± 17.9 mm3, and 144.9 ± 15.6 mm3 for U266 [Figure 3B], RPMI8226, and LP-1, respectively; P < 0.05) and in those inoculated with myeloma cells stably expressing the p17-70 fragment (76.6 ± 7.9 mm3, 85.4 ± 8.2 mm3, and 87.1 ± 9.6 mm3 for U266 [Figure 3C], RPMI8226, and LP-1 cells, respectively; P < 0.05), suggesting that PF4 and p17-70 attenuated the growth of the myelomas in the SCID-rab mice. The gene discussed is PF4; the disease is plasma cell myeloma.