SNAI1 and nasopharyngeal carcinoma: Although many of these gene expressions were different between the primary tumor and the LN and/or those of S26 and S18, as shown in Supplemental Table 1, there were only small percentages of genes simultaneously altered in both sets of screens, including the well-known markers for EMT and/or metastasis, such as Snail, Twist and Zeb1, indicating that this strategy was suitable to look for new regulators for NPC metastasis.