Clinical characteristics of patients in stem-like and differentiated subtypes.

**<p>p-value <0.01,</p>***<p>p-value <0.001. OSE Ovarian surface epithelium, NC not classified. In each dataset, p-values were corrected for family-wise error rate using Hommel’s method <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057799#pone.0057799-Hommel1" target="_blank">[46]</a>, except for the test for association with the Tothill et al. molecular subtypes.</p

Heatmap of gene expression and Kaplan-Meier survival curves for the stemness bipartition.

<p>(A) A heatmap of gene expression profiles of the 24 differentiated (green) and 121 stem-like (blue) tumors from the AOCS dataset <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057799#pone.0057799-Tothill1" target="_blank">[10]</a>. The tumors are ordered by increasing stemness molecular subtype score, and the 51 classifier genes are ordered from top to bottom by increasing over-expression in the stem-like subtype according to a pooled <i>t</i>-test. The Kaplan-Meier curves are with respect to (B) disease-free survival and (C) overall survival and are not significant at p<0.05, but this is possibly due to the small size of the differentiated subtype.</p

Validation of the stemness bipartition in independent ovarian cancer microarray datasets, as well as in the remaining AOCS dataset.

<p>In the remaining AOCS dataset, the stem-like subtype has strongly worse (A) disease-free survival (p<0.001) and (B) overall survival (p = 0.00127). In the (C) Crijns and (D) Dressman datasets, the stem-like subtype has significantly worse overall survival (p = 0.022 and p = 0.035, respectively).</p

Multivariate Cox proportional hazards models of the stemness bipartition to predict relapse-free survival when adjusting for two prognostic variables (A) residual disease and stage, (B) grade and stage or (C) grade and residual disease.

*<p>p<0.05,</p>**<p>p<0.01,</p>***<p>p<0.001.</p>1<p>In regression analyses, the ordinal variables stage and grade were broken into multiple components using default functions in R. However, only the linear components (levels treated as a continuous variable) are displayed in the table because the other components were not significant. Grade was also coded as a quadratic component (grade 2 vs. grades 1 and 3) and stage as both quadratic (stages 2 and 3 vs. stages 1 and 4) and cubic (stage 2> stage 4> stage 1> stage 3) components.</p

Shared characteristics of Types I and II ovarian cancer and the stem-like and differentiated subtypes [12].

<p>Shared characteristics of Types I and II ovarian cancer and the stem-like and differentiated subtypes <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057799#pone.0057799-Kurman1" target="_blank">[12]</a>.</p

The stem-like subtype is significantly overrepresented in basal-like breast cancer.

***<p>Fisher’s exact test p = 3.50×10⁻¹⁸ and p = 1.11×10⁻²⁷, Desmedt and Veridex datasets respectively.</p