The association remained significant in multivariate Cox regression analysis (including age, EMD, number of PET-positive focal lesions, anemia, ISS stage, elevated CRP level and number of prior treatment lines), confirming that the splenic 68Ga-Pentixafor signal can provide independent prognostic information in MM (HR 0.75, P = 0.009; Table 3). The gene discussed is CRP; the disease is anemia.