GAST and cancer: However, individual cancer cells invade the matrix in this system, and this was stimulated by dermal fibroblasts in combination with gastrin compared to either gastrin or fibroblasts alone (one-way ANOVA, G17 vs. G17 w/fibroblasts, p < 0.001; fibroblasts vs. G17 w/fibroblasts, p < 0.001; w/G17 vs. w/o G17, p = 0.023) (Supplementary Figure S2).