In general, GM-CSF is an essential factor for the differentiation and maintenance of myeloid cell lineage in bone marrow.13 Some reports showed that GM-CSF promoted recruitment of MDSC in tumour microenvironment;14,15 however, other reports showed that GM-CSF activated T-cell response in tumour.16 Furthermore, GM-CSF was reported to directly promote tumour cell proliferation.17 The role of GM-CSF in tumour microenvironment remains unclear. Here, CSF2 is linked to neoplasm.