Snail1 as a key prognostic biomarker of cancer-associated fibroblasts in breast tumors.

Accurate cancer diagnosis is crucial for selecting optimal treatments, yet current classification systems often include non-responders who receive ineffective therapies. Cancer-associated fibroblasts (CAFs) play a central role in tumor progression, and CAF biomarkers are increasingly recognized for their prognostic value. Recent studies have revealed significant heterogeneity within CAF populations, with distinct subtypes linked to different tumors and stages of disease. In this review, we summarize recent findings from patient samples and mouse models of breast cancer, focusing on gene signatures identified by single-cell RNA sequencing that define CAF subtypes and predict cancer prognosis. Additionally, we explore the genes and pathways regulated by Snail1, a transcription factor whose expression in breast and colon CAFs is associated with malignancy. Altogether these data emphasize the fibrotic and immunosuppressive roles of Snail1-expressing fibroblasts and unveil an undescribed streamlined Snail1-related gene signature in CAFs with prognostic potential in breast cancer and other solid tumors.