IL4 and neoplasm: (Gordon et al., 2017). In the tumour microenvironment, macrophages with the M2 phenotype polarized by IL-4, IL-10, etc., are often referred to as “tumour-associated macrophages” (TAMs). TAMs are a major component in leukocyte infiltration in tumour tissues (Hao et al., 2012; Noy & Pollard, 2014).