Rosenbaum JT, et al. - The proposition explored here was that gene expression profiles would complement clinical and histopathologic analyses in determining the well-characterized diseases and in subdividing nonspecific orbital inflammation (NSOI) into clinically relevant groups. Clear heterogeneity was unveiled through the gene expression profiling of patients with the lacrimal inflammatory disease. Comparison of the expression profiles indicated that a subset of patients with nonspecific dacryoadenitis could present with a limited form of sarcoidosis. In contrast, other patients with NSOI could not be distinguished from healthy subjects.