Table 1.

Other factors stimulate MDSC accumulation in hepatocellular carcinoma.

Molecule	Primary mechanism of action	Reference
HSC	Activation of the COX2/PGE2/EP4 and SDF-1/CXCR4 signaling pathways	(46, 47)
TAF	Activation of the SDF-1α/CXCR4 and IL-6/STAT3 pathways	(48)
AMPK	Suppression of the JAK/STAT, NF-kB, C-EBPβ, and CHOP signaling pathways	(49)
HIF-1α	Conversion of extracellular ATP to 5′-AMP through its direct transcriptional target, ENTPD2, and promotion of the interaction between CCL26 and CX3CR1	(50, 51)
PIWIL1	Induction of P38MAPK signaling	(52)
PKM2	Activation of PI3K-AKT and JNK signaling pathways and upregulation of HIF-1α expression	(53)
RIP3	Promotion of the interaction between CXCL1 and the cognate receptor CXCR2	(54)