In human studies, subpopulations of TANs can be polarised to an anti-tumour phenotype in response to low levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-γ in early lung cancer.11 Moreover, TANs isolated from colorectal cancer have anti-tumour properties.12 In contrast, tumour microenvironment cues polarise TANs to an immunosuppressive phenotype in the late stage of cancer.13,14 Therefore, the immunomodulatory phenotype of TAN depends in part on tumour stage and type. This evidence concerns the gene CSF2 and colorectal cancer.