PTTG1 and neoplasm: In addition, a comprehensive analysis of the five prognostic features was conducted, and finally, we identified a specific role in the tumor microenvironment based on the tryptophan metabolism-associated hub gene, PTTG1, and conducted a series of cellular experiments to validate the correlation between PTTG1 and tryptophan metabolism, as well as its promotional role in the process of proliferation, migration, EMT and apoptosis in LUAD.