The resistance of lung cancer cell line, H596, to Erbitux in co-culture with fibroblasts and a corresponding increase in cMet expression and activation compared to the mono-cultures (S5B Fig), indicate that these cells have become resistant to EGFR therapy and depend on HGF produced by co-cultured fibroblasts for survival in co-cultures (Fig 6B). Here, HGF is linked to lung cancer.