We added recombinant TIMP‐1 to a matched set of isogenic DLD‐1 CRC cell clones, in which either the endogenous KRAS wt allele (from here on referred to as DLD‐1 G13D cell line) or the KRAS(G13D) mutant allele (from here on referred to as DLD‐1 wt cell line) has been inactivated by targeted homologous recombination (Yun et al., 2009), respectively. The gene discussed is KRAS; the disease is colorectal carcinoma.