PIK3CA and neoplasm: After confirming that the global expression patterns of the 5000 genes were similar in organoids and primary tumor tissues, we tested correlations using 1090 key genes involved in carcinogenesis pathways from the hallmark gene sets v7; these genes were involved in Wnt/β-catenin, DNA repair, Notch, PI3K/AKT/mTOR, MYC target, P53, and KRAS signaling pathways.