Molecular profiling identifies two subgroups of lung adenocarcinoma with differences in smoker status. Unsupervised analysis of 39 AC cases identifies two AC groups, where one (AC1) comprises all never-smoker cases. Hierarchical clustering was performed on 706 Illumina probes with log2ratio SD >1 across the 39 cases using Pearson correlation and complete linkage. The color-coded beadchip annotation bar indicates which of the seven beadchips that a specific sample was hybridized to. Approximately Unbiased (AU) p-values (%) provided by pvclust  analysis using 1000 bootstraps are indicated for certain branches of the hierarchical tree, where values close to 100% indicate that clusters are highly supported by data.