Whole-exome sequencing in the GC PDOs revealed the well-documented driver mutations previously reported in GC, such as frequent alterations of CDH1 in diffuse type, TP53 in intestinal type and some other mutations involving RHOA, ERBB2, FGFR2, and MYC, and the similarities in the CIN and GS status to those previously reported in GC were also demonstrated. The gene discussed is FGFR2; the disease is gastric cancer.