SPP1 and neoplasm: There are even some biomarkers reflecting the interaction between tumor cells and the tumor microenvironment, which are relevant to tumor progression and metastasis, such as the sEV-miR-183-5p prognostic marker, a noncoding RNA embedded in small extracellular vesicles promoting the polarization of tumor-associated macrophages into the immunosuppressive M2 phenotype and upregulating SPP1, which represents a good candidate for a therapeutic target [23].