Fig. 5. Genome-wide association study data do not cluster by radiation exposure but by histotype for some tumors.

(A) Unsupervised hierarchical clustering of genome-wide association scans for tumor phenotypes reveals that the most significant clustering events often occur for the same histotype regardless of radiation exposure; these include mammary adenocarcinoma, thyroid adenoma, and hepatocellular carcinoma. (B) As expected, clustering genome scans for coat color demonstrates the expected results: that genome scans cluster together despite exposure group. The green line represents the 99% confidence level of the most significant dendrogram heights by permutations (−log₁₀ values permuted with genetic markers) to determine a distribution of dendrogram heights under the null hypothesis that no associations exist (C), demonstrating that the observed clusters are highly unlikely to occur randomly.