The quality of extracted total RNA was evaluated by RIN, which is calculated with Bioanalyzer (Agilent 2100). RNA sample scoring RIN > 6.0 were used for the following microarray analysis.
Gene expression profiling was compared among CDX2P‐G22Cre;Apcflox/flox;Braf LSL‐V600E/+ (n = 3), CDX2P‐G22Cre;Apcflox/flox;KrasLSL‐G12D/+ (n = 3), and CDX2P‐G22Cre;Apcflox/flox (n = 3) mouse tumors with a Mouse Gene 1.0 ST Array (Affymetrix). The arrays were scanned using a GeneArray scanner (Affymetrix), and gene expression data were analyzed using GeneSpring GX software version 11 (Agilent Technology). The robust multichip analysis algorithm was used for normalization to remove artifactual differences between arrays, and cut‐off values were set at less than 20% to eliminate poorly reproducible entities between chips.