BiDCG analysis of lung cancer data.

The set of patients described in Bhattacharjee et al. [39] include 21 patients with squamous cell lung carcinomas (SQ), 20 patients with pulmonary carcinoids (COID), 6 patients with small cell lung carcinomas (SCLC), and 17 healthy patients with normal lungs (NL). Gene expression patterns over 1543 relevant genes were collected for each patient. The biDCG procedure applied to these data identified 7 biclusters, marked in white on the specially constructed heat map shown in panel A. Bicluster SQ_A for example identifies a set of genes, named also SQ_A, that best identifies patients with SQ lung cancers. Similarly, the three subsets of genes NL_A, NL_B, and NL_C can be thought as containing signature genes for healthy patients, while the subsets of genes COID_A, COID_B, and COID_C contain genes that identify best COID patients. Panel B shows the DCG tree on all patients based on all genes, while panels C, D, and E show the equivalent DCG trees based on the gene subsets SQ_A, COID_A, and NL_A, respectively. The color coding for the DCG trees is: purple, SQ, red, NL, green SCLC, and blue, COID.