The expression of miR-141 in tumour cells decreases and the production of CXCL1 increases during MPE development, and miR-141 recruits Tregs into MPE via CXCR2, resulting in an enhanced immunosuppressive effect of Tregs that promotes the immune escape of tumour cells and exacerbates MPE formation. The gene discussed is CXCL1; the disease is neoplasm.