TGFB1 and neoplasm: To address whether Lepr is a direct transcriptional target of TGFβ receptor signalling in vivo, we performed an assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) analysis of FACS-purified TGFβ-reporter positive versus negative basal tumour populations (Extended Data Fig. 4b–d).