Regarding tumor DNA, there were two mutated genes in one patient (CDH1 and MUC6), five mutated genes in two patients (including BNC2, FAT4, APC, TP53, CREBBP), and ten mutated genes in two patients (CDH1, PIK3CA, SMAD4, MUC6, FAT4, APC, RNF43, KMT2D, CTNNB1, ARID1A). The gene discussed is PIK3CA; the disease is neoplasm.