The expression levels of these four genes were significantly increased in the tumors compared to those in the normal tissues, and 51.1% (47/92), 58.7% (54/92) 39.1% (36/92), and 52.2% (48/92) of the GC samples showed more than a 2-fold upregulation of TGFB1, TGFB2, ZEB1 and PTBP1, respectively (Fig. 8a-c and Additional file 1: Fig. S7a). Here, TGFB1 is linked to gastric cancer.