Further interrogation indicated that Irg1 upregulation in the liver of WD-fed mice was dependent on interferon receptor (IFNAR) expression but independent of Stat1 expression (Fig. 2c), implicating non-canonical type I interferon signaling or potentially Stat2 homodimers as being important to the upregulated Irg1 expression in the liver following WD18. This evidence concerns the gene IFNAR2 and Wilson disease.