The ESCC cell lines were treated with CCL21 (100 ng/mL), and qRT-PCR showed a remarkable increases in the mRNA level in KYSE410, KYSE450 and Eca9706 cells with a higher expression level of CCR7, while there was no significant change of MUC1 in KYSE150 with a lower expression level of CCR7 (Fig. 2c). Here, CCL21 is linked to esophageal squamous cell carcinoma.