PTEN and neoplasm: To broaden these findings to CNVs across a larger tumour sample, we carried out digital droplet PCR (ddPCR) for the genomic Erbb2/Neu, Grb7, Mien1, Pten and Atad1 loci on the tumour cohorts and matched spleen samples, using both snap-frozen tumour samples and DNA isolated from formalin-fixed paraffin-embedded (FFPE) blocks.