We noticed 6 genes (SFRP4, NOX4, HOXA11, NKX2-5, CDH16 and LOC100505875) were special up-regulated both in primary cancer and PM cancer, and 16 genes (LIPF, NKX6-2, MIXL1, CWH43, SULT1E1, CXCL5, REG1A, GHRL, NKX2-2, HTR1E, HPGD, ESRRG, CYP2C19, ADH1C, PNLIPRP3 and CEACAM5) were special down-regulated both in primary cancer and PM cancer. The gene discussed is REG1A; the disease is cancer.