Given the abundance of inflammatory cells (largely macrophages and dendritic cells) in PNF [34,35], and that GM-CSF signaling is known to modulate the tumor-immune microenvironment in many settings [7], we analyzed tissues sections to quantify the types of immune cells in the mouse PNF lacking Csf2a or Csfr2b (Figure 3). The gene discussed is CSF2; the disease is neoplasm.