Researchers in an early study on well-differentiated colorectal adenocarcinomas with lymph node (LN) metastasis reported loss of the proliferative marker Ki-67 in the cells along the invasive front in de-differentiated primary and secondary tumors, in contrast to the presence of high Ki-67 at the tumor center [42]. This evidence concerns the gene MKI67 and colorectal adenocarcinoma.