As expected, the expressions of USP3 and SMAD4 were both upregulated when Dicer was knockdown in the CRC cells with depletion of USP3 or SMAD4 (Fig. 2g,h), indicating that crosstalk between USP3 and SMAD4 was abolished after Dicer was silenced. This evidence concerns the gene SMAD4 and colorectal carcinoma.