Secondly, we analysed a locally derived cohort of invasive breast cancer samples (n = 44) using isoform-specific assays: quantitative RT-PCR was first performed using primers targeting exon 7/8 of WT1, in order to amplify all the known isoforms (Fig. 2A, Figure S1 in Additional file 1). The gene discussed is WT1; the disease is invasive breast carcinoma.