USP15 and lung adenocarcinoma: To explore the functional role of USP15 in human lung adenocarcinoma, we generated USP15-knockout (USP15KO) human lung adenocarcinoma A549 and USP15KO human non-small cell lung cancer H1299 cells using CRISPR/Cas9 gene-editing method (Fig. 2A, USP15KO A549; Fig. 2B, USP15KO H1299) as described in “Materials and methods”.