To further confirm whether Twist1 is directly involved in the Wnt/β-catenin pathway, we first screened four synthesized siRNAs and found that two of them (named si-Twist1#2, si-Twist1#4) significantly reduced the expression of Twist1 in two lung cancer cell lines (Additional file 2, Figure S3A and B). This evidence concerns the gene TWIST1 and lung cancer.