Dinse GE, Parks CG, Weinberg CR, et al. - This research was sought to assess if the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25‐year span in the US. Researchers assessed serum ANA by standard indirect immunofluorescence assays on HEp‐2 cells in 14,211 participants age ≥12 years from the National Health and Nutrition Examination Survey, with approximately one‐third from each of 3 time periods: 1988–1991, 1999–2004, and 2011–2012. They applied logistic regression adjusted for gender, age, race/ethnicity, and survey design variables to calculate changes in ANA prevalence across the time periods. The findings exhibit that in the US, the prevalence of ANA has increased considerably in recent years. The results considered that future research to ascertain factors underlying these increases in ANA prevalence could elucidate causes of autoimmunity and enable the development of preventative measures.