In analyzing the gene mutation of ovarian cancer, one research group established HGS-OC PDXs and reported a similar copy number variation to original tumor, and that the frequency of TP53 alterations in PDXs was 93%, BRCA1 mutation was 13%, BRCA2 mutation was 8%, consistent with the analysis in The Cancer Genome Atlas (TCGA) data 49. The gene discussed is BRCA1; the disease is neoplasm.