These are members of B7 family including B7–H2 (ICOS-L), B7–H3 (CD276), B7–H4 (B7x), V-domain immunoglobulin suppressor of T cell activation (VISTA), B7–H6, HHLA2 (B7–H5/B7–H7) and catabolic enzymes like indoleamine 2,3-dioxygenase 1 (IDO1), and others that are also contributed to the regulation of tumor immune microenvironment (TIME). Here, IDO1 is linked to neoplasm.