PRDX4 and colorectal carcinoma: Therefore, to determine how GSN and PRDX4 promote metastasis in CRC, short hairpin RNA (shRNA) for knockdown of GSN and PRDX4 or scrambled shRNA lentiviral particles (control group) were transfected into DLD-1 cells, and as a result, the levels of GSN and PRDX4 proteins were decreased, but not by the transfection of scrambled shRNA (Figure 5A).