Statistical evaluation revealed that smoking (HR=2.543, 95%CI: 1.159-5.583, P=0.020) and high expression of iASPP (HR=3.351, 95%CI: 1.310-8.575, P=0.012) were independent predictors of poor prognosis in lung adenocarcinoma patients with brain metastases.<h4>Conclusions</h4>This study revealed the interaction between epithelial cells and fibroblasts in the microenvironment of lung adenocarcinoma brain metastasis and implicate PPP1R13L as a potential prognostic indicator and actionable target, offering rationale for precision therapy against lung adenocarcinoma brain metastases. The gene discussed is PPP1R13L; the disease is lung adenocarcinoma.