Table 1.

Mechanisms of hepatic tumor-immune escape.

Attack			Defense
System	Mechanism	Ref.	System	Mechanism	Ref.
Fas/FasL	T-cell apoptosis	66	Tregs	Immunosuppression	73
PD-1/PD-1L	T-cell apoptosis	69	MHC-I	Antigen presentation	75
Galectin-1	T-cell apoptosis	72	B7-1/B7-2	Antigen presentation	76
			IDO	Immunosuppression	82

Two main strategies to escape from the immune response attack and defense have been demonstrated for HCC in experimental and/or clinical setting. Fas: CD95; FasL: CD95L; PD-1: programmed death-1; PD-1L: programmed death-1 ligand; Tregs: Regulatory T cells; IDO: Indoleamine 2,3 dioxygenase.