SPP1 and neoplasm: Myeloid cells infiltrated in the tumor tissues were sub-clustered into seven phenotypes, including monocyte, myeloid-derived suppressor cells (MDSCs), M1 macrophages, M2 macrophages, macrophages expressing Spp1 (Spp1_macrophage), proliferative_macrophages, and Osteoclast-like cells (Fig. 6A-C).