To validate our expression profiling analyses, six selected genes including top three overexpressed (COL6A3, SERPINH1 and PLEKHG1) and underexpressed (PGA4, KCNE2 and GIF) mRNAs were experimental verified using circulating mRNA extracted from 56 GC patients and 14 healthy subjects. The gene discussed is KCNE2; the disease is gastric cancer.