In both ovarian cancer data sets of our samples7 and The Cancer Genome Atlas (TCGA),23 expression of CD33 was positively correlated with expression of CSF2RA/B that is the receptor for GM-CSF (Fig. 6g; Supplementary Fig. S6a), indicating that GM-CSF could be an inducer of MDSCs. This evidence concerns the gene CSF2 and ovarian carcinoma.