In the context of PMN-MDSCs, co-culture of PMN-MDSCs with multiple myeloma cells upregulated key stemness-related transcription factors, including Nanog, OCT4, and SOX2 (Figure 2) [126]; prostaglandin E2 (PGE2) secretion from PMN-MDSCs was found to induce expansion of the ALDH+ CSC subset in human cervical cancer [127], and PMN-MDSCs upregulate CD44 and CD133 expression levels through phosphorylation of STAT3 in colorectal carcinoma [128]. This evidence concerns the gene PROM1 and cervical carcinoma.