SMAD2 and colorectal carcinoma: We further used siRNA against Smad2 to knockdown Smad2 expression (Figure 1B and 1C) and repeated the invasion assay, and we found that siSmad2 can also reduce the invasion activity to a similar level as hsa-miR-140-5p (Figure 2), suggesting that hsa-miR-140-5p impacts CRC invasion through Smad2.