CSF2 and neoplasm: GM-CSF has been reported as an immune activator that maintains the function of dendritic cells.30 On the other hand, reports have shown that GM-CSF inhibits lymphocyte activity through induction of MDSCs.31,32 We show that GM-CSF can potentiate the differentiation of myeloid cells into dendritic cells or MDSCs in the absence and presence of tumour supernatant, respectively (Fig. 5b).