Expression of NKD1 in lung cancer tissues and cell lines. (A). Compared with normal lung tissue (N1-N3), NKD1 protein expression was significantly decreased in lung cancer tissues (T1-T3) (P < 0.05). (B). NKD1 protein expression in BE1 and LH7 cells was lower than that in HBE cells, a normal human bronchial epithelial cell line (P < 0.05). In addition, NKD1 protein expression in BE1 cells (high metastatic potential) was lower than that in LH7 cells (low metastatic potential) (P < 0.05).