GAST and neoplasm: However, the invasion of tumor cells stimulated by the presence of fibroblasts was increased further by treatment with gastrin (one-way ANOVA, ECM w/ fibroblasts and G17 vs. ECM w/o fibroblasts and G17, p < 0.001; ECM w/fibroblasts vs. ECM w/fibroblasts and hG17, p = 0.002) (Figure 7B).