In the study by Boissiere-Michot et al., KRAS mutation was identified in 9/31 (29%) surgical specimens which major tumour regression is achieved in locally advanced rectal adenocarcinomas after radiochemotherapy, less than in the paired pretreatment biopsies (12/31, 39%) (Boissiere-Michot et al. 2012). This evidence concerns the gene KRAS and rectum adenocarcinoma.