To date little is known about the functional role of SLE-associated genes STS8IA4 and ARHGAP27. In order to infer the potential biological role of these two genes, we used the GeneNetwork approach, a functional-inference method based on the gene co-expression patterns extracted from microarray data from > 80,000 samples [36]. The gene discussed is ARHGAP27; the disease is systemic lupus erythematosus.