SOX2 and non-small cell lung carcinoma: TNFSF10 (also known as TRAIL) that was negatively correlated with SOX2 in the 105 NSCLC cell lines (Fig. 2) but not in the 178 lung SCC specimens is known to induce apoptosis; however, SOX2 siRNA did not induce apoptosis in the lung SCC cell lines that we investigated (Supplemental Figure 6), suggesting that TNFSF10 may be a SOX2 downstream gene in non-lung SCC cells.