NDRG4 and colorectal carcinoma: Numerous studies have also found that N-Myc downstream-regulated gene 4 protein (NDRG4) [17], secreted frizzled-related protein 2 (SFRP2) [1], secreted frizzled-related protein 1 (SFRP1) [18], and vimentin [19, 20] are associated with the occurrence of CRC.