Table 1. The functions of immune cells during hepatocellular carcinoma development

Characteristics	Types of immune cell	Cytokines/Chemokines	References
Protumorigenic	Regulatory T cells	IL-10 and TGF-β	13
	M2 macrophages	IL-10, Arg1, PD-L1	16–19
	MDSCs	CD34, CD33, CD15 and CD16	20–27
	TAN2	CCL2 or CCL17	32
	Natural killer T type I	OPN	37, 38
	T helper cells (Th9, Th17, Th22, and T follicular helper)	IL-17, IL-22	39–42
Immunosurveillance	CD8+ T cells	TGF-β- or IL-10	43–45
	CD4+ T cells	IFN-γ	46
	B cells	Granzyme B, CD20	51–53
	Natural killer T type II	IFN-γ, IL-4, TNF-α	47
	Dendritic cells	IL-12	48–50
	M1 macrophages	IL-6, IL-1β, TNF-α	17