Increased expression of ccl3, cxcl5, and cxcl1 has been shown following nanoTiO2 exposure in several in vivo mouse models; these findings were associated with the development of pulmonary inflammation, granulomas, emphysema, and pulmonary host defense [Driscoll et al.,1993; Park et al.,2010; Rossi et al.,2010]. Here, CXCL1 is linked to pulmonary emphysema.