FOXA2 and lung carcinoma: We next investigated whether FOXA2-DS-S can affect the expression of the associated coding gene, finding that FOXA2-DS-S is necessary for full expression of the FOXA2 gene (Fig. 5b; Additional file 4: Figure S15a), since its down-regulation by RNA interference results in reduction of FOXA2 expression in Huh7 liver cancer cells (Fig. 5b) and A549 lung cancer cells (Additional file 4: Figure S15a).