Although clinically promising in this field, several drawbacks make the interpretation of 18F-FDG PET challenging in multiple myeloma, especially at the time of initial diagnosis: as a heterogeneous disease, multiple myeloma can present with variable metabolic uptake, ranging from low to extremely high; additionally, anemia and G-CSF may stimulate BM uptake, reducing the detectability of axial targets. This evidence concerns the gene CSF3 and plasma cell myeloma.