SOX2 and esophageal squamous cell carcinoma: We showed that ATF/SOX2 up-regulated CDKN1A, one of the target genes of SOX2, and induced cell G1 cycle arrest more effectively than shSOX2 in SOX2-expressing EBC2 lung cells and TE4 esophageal SCC cells (Figure 4, Supplementary Figure 1, Supplementary Figure 2).