This score correlated strongly with the tumour cell proliferation signatures Oncotype Dx (ρ = 0.90–0.91, P < 0.001), a PCNA score (both ρ = 0.96, P < 0.001), and the novel Stathmin proliferation score (ρ = 0.77-0.79, P < 0.001; METABRIC cohorts, Supplementary Fig. 1F–K). Here, PCNA is linked to neoplasm.