Formalin fixed paraffin-embedded tissue blocks or fresh tissue samples are obtained from all patients prior to treatment. Tissue samples are analyzed by immunohistochemistry for the expression level of target proteins (MEK, p-MEK, ERK, p-ERK, Akt, p-AKT, RASSF1A, NORE1A and NORE1B); PCR for mutational status of target genes RAS, BRAF and EGFR); and in methylation-specific PCR for methylation of target gene promoters (promoters for RASSF1A, NORE1A and NORE1B). Samples are also analyzed by quantitative real-time PCR to compare methylation status. Fresh frozen tissue, when available, is evaluated by Western analysis to measure expression levels of target proteins.