Mouse heterozygous for urokinase-type plasminogen activator transgene

The present invention provides: a mouse with liver injury, in which uPA gene occurs in a heterozygous form, and which has a high degree of injury to hepatocytes originated from the mouse; and a method for producing the mouse with high efficiency. A method for producing a mouse with liver injury in which uPA gene occurs in a heterozygous form, said method comprising the steps of: (i) transforming a mouse ES cell with a DNA fragment which contains a liver-specific promoter/enhancer and urokinase-type plasminogen activator-encoding cDNA that is operably linked under the regulation by the liver-specific promoter/enhancer; (ii) injecting the transformed mouse ES cell produced in step (i) into a host embryo; (iii) transplanting the host embryo which is produced in step (ii) and into which the ES cell has been injected into the uterus of a foster mother mouse to produce a chimeric mouse; and (iv) mating the chimeric mouse produced in step (iii) to produce a transgenic mouse into which the DNA fragment has been introduced in a heterozygous form.