Immunobiology of hepatocarcinogenesis: Ways to go or almost there?

Table 1 Immune cells involved in tumor response

Cell type	Mechanism
	Pro-tumor	Anti-tumor
CD8+ T cells	Exhaustion of CD8+ T cells	Increased CD8+ T cells
	Upregulation of PD-1
CD4+ T cells	TH2 response	TH1 response
TH17 cells	IL-17 production via STAT-3
Treg cells	Increased Treg
	Impaired CD8+ T cells via CTLA-4
TAM	M2 (Th2 response)	M1 (Th1 response)
	Increased galectin-9 via TIM-3
	Expression of B7-H1
	Induction of TH17
TAN	N2 phenotype	N1 phenotype
	Angiogenesis via Treg
MDSC	Induction of Treg and TAM
	Suppress CD4+ T cells
	Suppress NK activity
NK cells	Increased CD56dimCD16pos	Increased CD56brightCD16neg
	Increased Treg

PD-1: Programmed death 1; IL: Interleukine; STAT-3: Signal transducers and activators of transcription 3; TAM: Tumor associated macrophages; MDSC: Myeloid derived suppressor cells; TAN: Tumor associated neutrophils; NK: Natural killer; T_reg: Regulatory T cells.