Some of the well-known negative regulatory cells and soluble factors include myeloid-derived suppressor cells (MDSC), innate lymphoid cells (ILC), tumor-associated macrophages (TAM), regulatory CD4+ T cells (Tregs), regulatory B cells (Bregs), transforming growth factor β (TGF-β), interleukin-10 (IL-10), adenosine, granulocyte-macrophage colony-stimulating factor (GM-CSF), prostaglandin E2 (PGE2), and L-Kynurenine (Artis and Spits, 2015; DeNardo and Ruffell, 2019; Facciabene et al., 2012; Sarvaria et al., 2017; Tauriello et al., 2018). Here, CSF2 is linked to neoplasm.