design: 8-week-old female PyMT-N-engrafted S100a8-cre, Ft1-fl/fl mice were euthanised for collection of the tumour tissue, where total RNA was isolated using standard protocol. The mRNA was enriched, fragmented and reversibly transcribed into cDNA. The purified double-stranded cDNA was end-paired, sequence-added, ligated to the sequencing adapters and amplified for library construction before eventually sequenced. The standard bioinformatic workflow was then applied for analysis.