In lung adenocarcinoma, 18 genes (SLCO1A2, PYROXD1, RECQL, LDHB, CMAS, KIAA0528, ETNK1, ASUN, FGFR1OP2, TM7SF3, MED21, MRPS35, KLHDC5, CCDC91, FGD4, DNM1L, YASR2, and KRAS) in 12p12.1 were found to have increased copy number and coamplified with KRAS, 88.9% (8/9) genes in our study were included. This evidence concerns the gene MED21 and lung adenocarcinoma.