Figure 4.

Distant disease-free survival of basal-like and non-basal-like tumors within the ER-negative tumor entity. The basal phenotype was defined by using immunohistochemistry (a), cDNA microarray and the top 500 gene set for the basal cytokeratin-immunopositive tumors (b) or cDNA microarray and the intrinsic gene set of Sorlie and colleagues [7] (c). There is no difference in survival between basal-like and non-basal-like tumors within the ER-negative tumor subgroup.