Finally, as our group has been interested in use of live attenuated vaccines for inducing immunity to P. aeruginosa[47], [48], [49] identification of factors like the Type IVa pili whose loss promotes mucosal colonization but also compromises the organism's ability to disseminate, even during neutropenia, suggests that Type IVa pilus-deficient strains might be part of an attenuated oral vaccine that maximizes GI colonization, and hence immunization, potential, while not being proficient at causing serious systemic disease. This evidence concerns the gene SGCG and neutropenia.