Seric Ig production in Arte^Δ/− mice. Sera from 9- to 18-week-old Art^fl/− and Art^Δ/− mice were collected, and total IgM, IgG1, IgG2b, IgG3, and IgE (μg/mL) were determined by ELISA. None of the differences between groups reached statistical significance (.46 < P < .97).