Nonhuman animal and use for same

A method for evaluating a drug discovery target protein, comprising:

• Step 1 of administering an auxin analog intraperitoneally or orally in an effective amount of 10 mg/kg or less per day to a genetically modified rodent which has a tissue-specific disease, in which an auxin-inducible degron system controls degradation of a target protein in a living body, and which has cells, throughout the body, containing a chromosome containing a first nucleic acid that encodes a mutant TIR1 family protein having a mutation at an auxin-binding site and having an affinity to the auxin analog, and
• a chromosome containing a second nucleic acid that encodes a degradation tag containing at least a part of an Aux/IAA family protein and having an affinity to a complex of the mutant TIR1 family protein and the auxin analog and a third nucleic acid that encodes a target protein linked upstream or downstream of the second nucleic acid are provided to cells throughout the body thereof, wherein the mutant TIR1 family protein is a protein in which an F74 of OsTIR1 has mutated to A, G, or S,
• wherein the auxin analog is a compound represented by the following general formula (I) or an ester thereof:
• and wherein R10 is a cyclic aliphatic hydrocarbon group in which a substituent may be present and some carbon atoms that configure a ring may be substituted with heteroatoms or an aromatic hydrocarbon group in which a substituent may be present and some carbon atoms that configure a ring may be substituted with heteroatoms;
• Step 2 of inducing, by the auxin-inducible degron system, degradation of the target protein in the living body in each cell;
• and
• Step 3 of observing an influence of the degradation of the target protein on diseased tissues and normal tissues.