Through a series of bioinformatics, RACGAP1, a key stemness gene, was screened, and it was verified that RACGAP1 affects cell proliferation, migration and cell cycle regulation by cell phenotyping, in vivo experiments in animals, and flow cytometry analysis, thus affecting stemness, and thus it is expected to be used as a therapeutic direction and target for lung adenocarcinoma in the future. The gene discussed is RACGAP1; the disease is lung adenocarcinoma.