NDRG4 and colorectal carcinoma: In addition, a stool DNA test (sDNA test), which includes quantitative molecular assays for KRAS (kirsten rat sarcoma viral oncogene) mutations, aberrant NDRG4 (N-myc downstream-regulated 4) and BMP3 (bone morphogenetic protein 3) methylation, and a hemoglobin immunoassay [5, 6, 13], has culminated in the development of an FDA approved, clinically available stool-based CRC screening test [2].