Administration of exogeneous TGF-α and amphiregulin did not induce migration of the colorectal cancer cell lines (Supplementary Figure 4A), while blocking TGF-α and amphiregulin action did not diminish the effects of CCL20 in inducing CCL20 secretion (Supplementary Figure 4B) or proliferation (Supplementary Figure 4C). The gene discussed is TGFA; the disease is colorectal cancer.