Table 1.

Quick guide for phenotype identification of the main immune cells within the tumor microenvironment.

Lineage	Cell		Function	Positive	Ref.
Lymphoid	T cells	Cytotoxic T cells	Immunostimulatory	CD3, CD8	133,134
		Helper T cells	Immunostimulatory	CD3, CD4	133, 134
		Gamma delta T cells	Immunostimulatory	CD3, γδTCR	136,136
		NK T cells	Immunostimulatory	CD3, CD161, CD94, CD1d-α-GalCer	137,138
		Memory T cells	Immunostimulatory	CD3, CD27, CD45RO	139,140
		Regulatory T cells	Immunosuppressive	CD4, CD25, FoxP3	141,142,143
	B cells	Plasma cells	Immunostimulatory	CD38, CD138	141, 142, 143
		Memory B cells	Immunostimulatory	CD19, CD20, CD27, CD38	141, 142, 143
		Regulatory B cells	Immunosuppressive	CD19, IL10, CD1d	144,146
	NK cells		Immunostimulatory	CD16, CD56	144, 145, 146
Myeloid	Tumor-associated macrophages (TAMs)	M1 phenotype	Immunostimulatory	CD68, iNOS, HLA-DR, CD80	148,149
		M2 phenotype	Immunosuppressive	CD68, CD163, VEGF, CD206	148,149,150
	Myeloid derived suppressor cells (MDSC)	Polymorphonuclear (PMN-MDSC)	Immunosuppressive	CD11b, CD15 (or CD66b), CD33	148, 149, 150
		Monocytic (M-MDSC)
	Tumor-associated neutrophils (TANs)		Can be pro- or anti-tumor activity	CD66b	148, 149, 150
	Dendritic cells (DC)		May be defective in TME as terminally differentiated myeloid DC	MHCII, CD103 or CD11b	153,154,155