As we previously showed that extracellular NAMPT does not affect macrophage polarization,[27] we conclude that it must be intracellular NAMPT that is involved in TAM polarization in response to secreted factors, such as lactate, rather than extracellular NAMPT from tumor cells, which is removed from the conditioned medium by size exclusion (<3 kDa) (see Figure 3D). This evidence concerns the gene NAMPT and neoplasm.