BTG2 and breast cancer: We verified the negative relationship between BTG2 and mast cell activation in breast cancer through our sc-RNA sequencing data and TCGA database, and confirmed that mast cells lacking BTG2 were more prone to produce the activation marker trypsin, which activated the PAR2 receptor-MEK pathway on precursor fibroblasts to induce myofibroblast subpopulations and the secretion of collagen.