Fibroblast growth factors (FGFs) have been implicated in the pathobiology of autoimmune inflammation on the basis of their angiogenic properties, as well as their increased expression at inflammatory sites. In order to better evaluate the role of FGF-1 in the renal disease of mice that develop spontaneous lupus-like clinical features, we examined the expression of FGF-1 mRNA and protein in the kidneys of the murine MRL lpr/lpr strain. Both Northern and Western blot analyses demonstrated that FGF-1 levels do not increase in the kidneys of this particular autoimmune mouse strain as a function of renal disease. These results suggest that FGF-1 may not be involved in the pathogenesis of autoimmune nephritis in MRL lpr/lpr mice.