These results suggest that myeloid ABCA1 may be important in the accumulation of granulocytic MDSCs (Ly-6G+Ly-6CLo) whereas myeloid ABCG1 may govern the frequency of monocytic MDSCs (Ly-6GnegLy-6CHi) in the tumor microenvironment. Here, ABCA1 is linked to neoplasm.