Afatinib markedly inhibited the growth of EGFR-overexpressing DiFi cells (IC50 = 45 nM) and showed activity across other colorectal tumour lines, with IC50 values ranging from 0.33 μM in CCL-221 cells to 1.62 μM in HCT-116 cells. This evidence concerns the gene EGFR and colorectal neoplasm.