Billing et al. assessed the usefulness of patient-reported xerostomia in the diagnosis of SS by comparing three groups, patients with SS, patient with dry mouth syndrome without SS and patients with incomplete SS (defined by the presence of a focus score > 1⁄4 mm2 or anti-SSA or anti-SSB autoantibodies but not meeting AECG criteria for SS classification). The gene discussed is SSB; the disease is xerostomia.