The Kaplan-Meier plotter tool (http://kmplot.com/analysis/) was used to generate survival curves combining KRT5 (Affymetrix probe 201820_at) and KRT6 (Affymetrix probe 209126_x_at detects all KRT6 isoforms) mRNA data from 13 public ovarian cancer datasets . The Kaplan-Meier analysis was performed on the 2015 version database (n = 1648) and patients were split by the best cut-off selected by the online plotter tool . PFS and OS data was available for 922 and 956 stage III/IV serous ovarian cancer patients, respectively. cBioPortal (http://www.cbioportal.org/) was used to assess correlations between KRT5 and KRT6 expression levels with clinicopathological parameters features in the TCGA 2011 dataset [62, 63].