Based on a heat map representation of their gene expression patterns, the human lung tumors were heterogeneous in their expression patterns; however, a subset of tumors (9 of 84 [11%] in the Harvard cohort and 10 of 86 [12%] in the Michigan cohort) exhibited an expression pattern similar to that of the EGFR-mutant NSCLC gene signature (Fig. 2B). This evidence concerns the gene EGFR and non-small cell lung carcinoma.