Tumor-educated neutrophils activate the AKT and p38 pathways in mesenchymal stem cells by secreting inflammatory factors (including IL-17, IL-23, and TNF-α), facilitating their conversion into cancer-associated fibroblasts (CAFs), which promotes the proliferation, migration, and invasion of gastric cancer cells in vitro and accelerates their growth and metastasis in vivo. The gene discussed is IL17A; the disease is cancer.