CCL2 and neoplasm: While NFPAs cannot be sampled serially over time, we hypothesize based on our data that NFPAs start out as the first type, attracting monocytes that they convert to TAMs and M2 polarize, enabling tumor proliferation and invasion, but, over time, NFPAs transition to the latter type as the M2 TAMs suppress NFPA MCP-1 production so that the NFPAs slow their monocyte attraction and the NFPA cells increase their GM-CSF production driving the TAMs that are present to an M1 subtype which is less supportive of tumor growth and invasion (Figure 6).