Moreover, the generation of therapy resistant cell clones harboring additional EGFR mutations or amplifications during therapy as well as the overexpression and amplification of EGFR regulating genes, e.g. ERFI1, have already been reported [2], [16] Therefore, the genomic investigation of single tumor cells that either reside in the blood or in the bone marrow may help to improve predictive molecular diagnostics. The gene discussed is EGFR; the disease is neoplasm.