CHST3 and cancer: Interestingly, the elimination of Gr-1+ cells by anti-Gr-1 antibody abolished the effect of HSD on tumour growth, suggesting that MDSCs play an essential role in the antitumour activity of HSD, though anti-Gr-1 antibody may also affect IMCs, MDSCs and neutrophils (studies have shown that IMCs differentiate into MDSCs in cancer, and PMN-MDSC are pathologically activated neutrophils54,55).