Figures 3c and 3d show the fitted and predictive ability of these two factors used in a binary regression model fit to progesterone receptor status. There is no significant correlation in tumor expression between the PgR and ER factors (Figure 2b). Gene ontology for the genes in the PgR specific factor (Table 2) bear out some of the known links between progesterone and RNA metabolism in breast cancer [30]. This evidence concerns the gene ESR1 and neoplasm.