Firstly, many of the studies showing these metabolites affect collagen production have been carried out in the context of activated fibroblasts in wound healing, fibrotic disease and acutely TGFβ-treated fibroblasts, rather than CAFs derived from cancer patients, although gene expression data suggests these pathways are also upregulated in the tumour stroma. The gene discussed is TGFB1; the disease is neoplasm.