Among these six genes, the expression level of bone morphogenetic protein 1 (BMP1), collagen 1A1 (COL1A1), and signal transducer and activator of transcription 3 (STAT3) is continuously increased from gastritis to the progression of cancer, while expression of GATA-binding factor 6 (GATA6), SRY-bo× 2 (SOX2) and forkhead box protein A2 (FOXA2) shows a progressively decreased trend (Fig. 1). Here, COL1A1 is linked to cancer.