Impact of FXIII deficiency on liver injury after APAP overdose. FXIII^−/− mice and WT mice were treated intraperitoneally with saline vehicle or 300 mg/kg APAP, and liver and citrated plasma were collected 24 hours after APAP challenge. (A) Plasma ALT activity was determined using commercial reagents (n = 4-5 mice/group for vehicle treated and 15-20 mice/group for APAP challenged). (B) Area of centrilobular necrosis was quantified as described (n = 9 mice/group). (C) Representative photomicrographs of H&E-stained liver sections (necrosis denoted by black arrowhead). Data expressed as mean ± standard error of the mean. *Significantly (P < .05) different from vehicle-treated mice of the same genotype.