PGR and cancer: Unblinding this analysis to the clinical annotation of each sample revealed that the 2 mostprominent dendrogram groups were primarily distinguished by lack of ER-positive (2/7) or PR-positive cancers (2/7) in the first group and the presence of ER-positive (9/13) or PR-positive cancers (8/13) in the second group; these differences did not quite achieve statistical significance (Fisher Exact test, p = 0.16).