Thus, our study confirmed the negative correlation between CCR7 and let-7a expression in ESCC, which strongly suggests that let-7a, suppresses the expression of CCR7. Regarding the direct interaction between CCR7 and let-7a, Kim et al. used the luciferase assay to show that let-7a directly regulates CCR7 expression by binding with its 3′-UTR [10]. Here, CCR7 is linked to esophageal squamous cell carcinoma.