LGR6 and esophageal squamous cell carcinoma: We also observed a significantly positive correlation in mRNA expression between XCL1 and LGR6 for ESCC cell lines (Supplementary Fig. 12d, Pearson’s correlation r = 0.59, p = 0.004), further highlighting the association between NK marker XCL1 and the stemness signature in ESCC cell lines.