To determine the role of HMGA1 proteins in chemoresistance we have analyzed the resistance to antineoplastic drugs of (i) the human colon carcinoma cells (GEO) that are sensitive to the epidermal growth factor receptor (EGFR) inhibitors cetuximab (CTX) and gefitinib, and that express barely detectable levels of HMGA1, and (ii) CTX-resistant GEO (GEO CR) cells that express high HMGA1 protein levels and are generated through in vivo continuous treatment with the drug followed by tumor explant and in vitro stabilization of the deriving resistant cancer cell lines [8]. Here, EGFR is linked to colon carcinoma.