CXCL12 and plasma cell myeloma: Beider et al. demonstrated that CXCL12 production and CXCR4 expression in multiple myeloma cells were higher compared to healthy counterparts, and the presence of M2 TAMs was linked to a reduction of M1 TAMs and T cell infiltration, as well as IFN-γ production [228], all of which contribute to an immunosuppressive protumor environment.