There were no significant correlations between the circulating levels of type IV collagen in the CLM group and gender (p = 0.89), age (p = 0.32), the localization of the primary CRC (p = 0.48), T stage (p = 0.69), N stage (p = 0.13), CEA levels (p = 0.14), size of the largest CLM (p = 0.14), number of CLM (p = 0.075) and time interval from CRC to CLM (p = 0.09). This evidence concerns the gene CEACAM5 and colorectal carcinoma.