RB1 and neoplasm: To compare the observations made in TCLs with TNBC tumours, we used the same approach of exploiting RB1 gene mutation/copy number status and RB1 mRNA expression profiles to classify 140 The Cancer Genome Atlas (TCGA) triple-negative breast tumours [27] according to Rb status; this approach identified 48 Rb-defective TNBC tumours and 92 where Rb was not altered.