Distribution of the expression of the basal-like metagene among TNBC of cohort-A. The bimodal distribution of the expression of the basal-like metagene among the 394 TNBC samples in the finding cohort-A is shown. A mixture (black line) of two normal gaussian distributions (blue and red lines) was fitted to these data. The interception of the two gaussians was derived as a cutoff (0.0014) for the definition of basal-like tumors. Similar results were obtained for the validation cohorts-B, and -C, as well as from all samples combined.