To analyze the prevalence of anti-Rpp25 antibodies in different cohorts, anti-Th/To-positive sera (n = 8 identified by IP), unselected SSc samples (n = 70) and disease and healthy controls (n = 367) were tested using the anti-Rpp25 assay on the BIO-FLASH instrument (Figure 3). The gene discussed is RPP25; the disease is systemic sclerosis.