Briefly, these findings were as follows: (1) CRC cases in advanced stages (III and IV) had higher AAT serum concentrations than those in early stages (I and II); (2) the gene frequency of the severe deficiency Pi*Z allele, and the prevalence of the Pi*MZ, Pi*SZ and Pi*ZZ deficiency phenotypes were higher in CRC patients than in controls; and (3) CRC patients with the Pi*MZ genotype tended to develop more locally advanced tumors, had a greater need for postoperative chemotherapy, and had a greater rate of mortality from causes directly related to the CRC than did subjects with the MM genotype. This evidence concerns the gene SERPINA1 and colorectal carcinoma.