EGFR and cancer: These data show that (1) the assay distinguished cancer from stromal cells, and (2) while the irradiated feeder fibroblasts enhanced the growth rate of cancer cells (for example, MGH121-1, MGH134-1, MGH707-1, MGH045-1, and MGH051-1), resistance to EGFR or ALK inhibition is not conferred by the irradiated fibroblast feeder layer.