We firstly evaluated BM CX3CL1 levels in our cohort of 111 patients, including 16 patients with monoclonal gammopathy of undetermined significance (MGUS), 25 with smoldering myeloma (SMM), and 70 with active MM, and 10 healthy donors (HD) as controls. This evidence concerns the gene CX3CL1 and smoldering plasma cell myeloma.