(A) IHC representative images of low and high HSDL2 expression on slides from human lung adenocarcinoma tissues and adjacent normal tissues. (B) Protein expression levels of HSDL2 in human lung adenocarcinoma tissues and adjacent normal tissues detected by IHC. (C) Kaplan–Meier survival curves for patients with lung adenocarcinoma based on HSDL2 expression in cancer tissue. (D) HSDL2 mRNA expression levels in human lung cancer cell lines (H1975, A549, SK-MES-1, H1688 and H1299) and normal human lung epithelial cell line (BEAS-2B). (E) HSDL2 mRNA expression levels in H1299 cells detected by RT-PCR. GAPDH was used as an internal control. (F) HSDL2 protein expression levels in H1299 cells detected by Western blot. GAPDH was used as an internal control. NC, transfected with empty vector, KD, transfected with HSDL2 shRNA vector. *P<0.05, **P<0.01, ***P<0.001. All data are presented as mean ± SD from three independent experiments.