Decreased RB1, ERCC5, and DSP3 in CRC, amplification of FGGR1 and deletion of BRCA in EGC, an increased copy number of RIT, FGFR1 and ERBB2, decreased MYBL1 and PRKDC in HNC, alteration of KRAS and CDK5 in OC, alteration of CDKN2A/B in PAAD, amplification of AR in PRAD, copy number decreases in MDM2 and CDK4 in STC, and increased TERT and SDHA in TC were detected in metastatic cancer compared to the original tissues. The gene discussed is MDM2; the disease is pancreatic adenocarcinoma.