CD276 and cancer: B7-H3 is expressed in different cells in the tumor microenvironment such as cancer cells, cancer stem cells, dendritic cells, pro-tumor type 2 macrophages, myeloid-derived suppressor cells, monocytes, endothelial cells (ECs), NK cells and cancer-associated fibroblasts which indicates the extensive engagement of the B7-H3 ligand/receptor interaction within the tumor region (67).