IL1B and neoplasm: Other studies that focused on soluble mediators of the TME found that interleukin-1β (IL-1β) secreted by the tumor stroma in PDAC promotes polarization of macrophages to the M2 phenotype, and proliferation of myeloid-derived suppressor cells (MDSCs), regulatory B cells (Bregs), and T-helper 17 (Th17) cells, which promote tumorigenesis [16,17].