SOX2 and small cell lung carcinoma: Interestingly, the expression levels of SOX2, a recognized oncogene in small-cell lung cancer [41], are downregulated upon arsenic trioxide in lung cancer cells [42] and we have also observed downregulation of SOX2 upon TRIT1 shRNA-mediated depletion (Table S1), reinforcing again the link between TRIT1 and arsenic trioxide.