Cross-analysis of mice harboring xenografts from the same original tumor and treated with each of the different modalities revealed subgroups with preferential sensitivity to AZD6244 (12.5%), BEZ235 (35%), or AZD6244 + BEZ235 (42.5%); another subgroup (10%) showed equivalent response to any treatment....sequenced for the presence of hotspot mutations in KRAS and NRAS (exon 2: codons 12 and 13), BRAF (exon 15: codon 600), and PIK3CA (exon 9: codons 542, 545, and 546; exon 20: codon 1047), as well as for the presence of rare mutations in KRAS and NRAS (exon 3: codon 61; exon 4: codon 146).