T4 (A) and T3 (B) concentrations in livers of 7-, 12-, 15-, and 18-day-old WT (squares) and XAA (Csbm/m/Xpa-/-) (circles) mice (n = 3/group; each time point of Csbm/m/Xpa-/- mice represents pooled tissues). Activities of D1 (C) and D3 (D) in livers of 7-, 12-, 15-, and 18-day-old WT and XAA (Csbm/m/Xpa-/-) mice (n = 3/group). T4 (E) and T3 (F) concentrations and D1 activity (G) in livers of 4-, and 18-week-old WT (black bars) and MAA (Ercc1-/Δ-7) (white bars) mice (n = 3/group). D3 mRNA expression in livers of 13-week-old and 130-week-old mice (H). D1 (black bars) (I) and D3 (grey bars) (J) activities in livers of 26-, 52-, and 104-week-old WT mice (n = 5/group). Values represent mean ± SE per group. * P < 0.05; ** P < 0.01; *** P < 0.001; # P = 0.051.