Table 1.

B-7 family of receptor ligands expressed by antigen presenting cells and various malignancies: CD cluster derivation; B7.1 known as CD80; B7.2 known as CD86; CD-28 and CD-152 present on T-naïve cells; ICOS inducible costimulatory ligand; (+) with and (−) without; CD152 also known as CTLA4 cytotoxic T lymphocytes antigen-4; PD-1 programmed death-1 also known as CD279; PD-L1 programmed death-ligand 1 known as B7-H1 or CD274; PD-L2 programmed death-ligand 2, known as CD273 or B7-DC B-7 dendritic cell; IFN-γ interferon gamma; IL-2 interleukin 2; Ref reference.

B-7 family molecules	CD-designation	Major ligands on immune cells	Role immunity activation versus immune suppression	Malignancies expressing B-7 molecules	Ref
B7.1	CD80	CD28; CTLA4 (CD152)	(+) 2nd signal activation (−) second signal anergy	CD-80 on acute myeloid leukemia cells	[37]
B7.2	CD86	CD28; CTLA4 (CD152)	(+) 2nd signal activation (−) second signal anergy	CD-86 on chronic lymphatic leukemia cells	[46]
B7-H1 (PD-L1)	CD274	PD-1 (CD279)	Ligating PD-1 on T-cells suppresses CD8+ response	None	[47]
B7-H2; B7-H3; B7-H6; ICOS	CD275	CD278	Immune suppression	Dendritic cells infiltrating malignancies; cancer cells: hematologic malignancies, breast, gastrointestinal, lung, melanoma, bladder, and genitourinary cancers	[48]
PD-L2 B7-DC	CD273	PD-1 (CD279)	Immune suppression reduces IL-2 and IFN-γ secretion, decreases proliferation and cytotoxicity, and induces apoptosis in activated T-cells	Primary mediastinal (thymic) large B-cell lymphoma	[49]