There was a significant positive correlation between CCL2, CCR2, CXCL1, CXCR2 expression and diethylnitrosamine treatment time in the primary rat HCC model (r = 0.70, p < 0.0001; r = 0.74, p < 0.0001; r = 0.67, p < 0.0001; r = 0.71, p < 0.0001; respectively) (Fig. 2B–E). The gene discussed is CCL2; the disease is hepatocellular carcinoma.