Figure 1. Flow chart of the present study. This study was divided into 5 research modules sequentially. (1) Data collection. Lung adenocarcinoma (LUAD) gene expression datasets were retrieved from the public gene expression omnibus (GEO) and the cancer genome atlas (TCGA) databases, respectively. (2) Prognostic subtype construction. Prognostic subtypes were constructed based on prognostic chromatin regulators. (3) Key prognostic gene identification. Key prognostic genes were identified by Cox regression and the least absolute shrinkage and selection operator (LASSO) analyses. (4) Prognostic signature establishment. Prognostic signature was established and evaluated. (5) Clinical feature and immunological feature analyses. The relationships of prognostic subtypes, prognostic genes and signature with clinical characteristics and immunological features were analyzed.