Abstract: Disclosed are a method of detecting the presence or absence of a single nucleotide polymorphism of a gene, for prediction of the risk of developing drug-induced lung injury, or for improving a therapeutic method, and a kit for carrying out the detection method. The detection method is characterized by comparing an ABCB1 gene in a biological sample with a wild-type ABCB1 gene to detect the presence or absence of a single nucleotide polymorphism in the ABCB1 gene in the biological sample, in particular, by determining the nucleotide at position 3751 of the CDS of the ABCB1 gene. The kit comprises an oligonucleotide probe which specifically binds to a single nucleotide polymorphism in an ABCB1 gene under selective binding conditions, or an oligonucleotide primer which amplifies a nucleic acid sequence comprising a single nucleotide polymorphism in an ABCB1 gene.