Using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases for pathway enrichment analysis of sequencing results, we found that the high‐frequency signalling pathways such as PI3K‐AKT, mTOR, AMPK, MAPK and P53 were consistent with common gene mutations in breast cancer (Figure 3C,D), which further indicated that PDOs retained the heredity of parental tissue and provided a basis for subsequent drug screening. Here, PIK3CA is linked to breast cancer.