TP53 and pancreatic neoplasm: Total RNA was isolated from the PDX-M sample (G4), and the genotypes of 4 major pancreas cancer driver genes (KRAS, TP53, SMAD4, and CDKN2A) were identified by RT-PCR and direct sequencing and then compared to those in the established pancreas cancer cell lines, MIA PaCa-2 and PANC-1 (Supplementary Table S2).