To start elucidating the role of USP39 in non-small cell lung cancer (NSCLC), we first performed a gene set enrichment analysis (GSEA) with gene expression data from lung adenocarcinoma patients obtained from The Cancer Genome Atlas (TCGA) public database (https://portal.gdc.cancer.gov/) covering the largest group of NSCLC. The gene discussed is USP39; the disease is lung adenocarcinoma.