Currently, in clinical practice, the detection of MET amplification through NGS is largely based on the principle of read depth, which ultimately calculates the amplification multiple of MET relative to normal cells. However, since the samples used in NGS sequencing are not all tumor tissues and include a portion of normal tissues, the NGS results cannot truly reflect the absolute copy number of MET in tumor cells. In addition, MET gene amplification including focal amplification and polysomy. Focal amplification refers to an increase in the copy number of the MET gene (or the surrounding region), while the copy number of genes in other chromosomal regions does not change significantly. Polysomy refers to an increase in the copy number of the entire chromosome (or a large section of the chromosome). We will use the NGS CNV results to estimate the proportion of tumor content in the sample, and convert the CN (Copy number) value of MET into GCN (gene copy number). Also, We will use the CNV results of multiple genes identified by NGS and the changes in heterozygous SNP VAF to distinguish whether the amplification type of MET belongs to focal or polysomy.