A group of non-cancerous cells that grow in and around tumours are more diverse than formerly thought.

Pancreatic cancer is one of the deadliest cancers, possibly in part because the tumours are surrounded by relatively large amounts of connective tissue called stroma, which promotes their growth. To learn more about the stroma, David Tuveson at Cold Spring Harbor Laboratory in New York and his colleagues grew 3D mouse pancreatic tumours and cultured them with pancreatic cells that develop into connective-tissue cells called fibroblasts. This yielded two subgroups of fibroblasts — one that sits next to and interacts with the cancer cells, and another that is located farther away and produces tumour-boosting inflammatory molecules.

These fibroblasts could have both pro- and anti-tumour effects, which may explain why some therapies that target the stroma fail to curb tumour growth, the authors say.

J. Exp. Med. http://doi.org/b2jf (2017)