In addition, RACGAP1 expression levels were increased across different stages of LUAD (Fig. 4d; compared to normal lung tissues, all P < 0.05), with late-stage tumor tissues exhibiting higher expression levels than did early-stage tumor tissues (Fig. 4d; stage 4 vs. stage 1; P < 0.05). The gene discussed is RACGAP1; the disease is neoplasm.