Chiu et al. have shown that hypoxia in the tumor microenvironment of the HCC can pave the way for MDSC infiltration via the hypoxia-inducible factor (HIF)-dependent regulation of the CCL26/C-X3-C motif chemokine receptor 1 (CX3CR1) pathway [33]. The gene discussed is CX3CR1; the disease is hepatocellular carcinoma.