BAD overexpression inhibits H1299/SPC-A1 cell tumorigenic activity. Cells (1 × 106 cells in 150 μl) were injected subcutaneously into the backs of BALB/c-nu/nu nude mice. After 4 weeks, tumour weights (A) and volumes (B) were significantly decreased in BAD overexpression groups compared with H1299/SPC-A1-NC and H1299/SPC-A1 groups. The xenograft tumors were processed for H&E staining (C). Representative examples of proliferative marker ki-67 staining in xenograft tumor tissues are shown (D). And data were represented as the mean Ki-67 index ± SD (E). Original magnification, × 200. Arrows indicate positive staining of nuclei. Bar: 50 μm. Data are expressed as the mean ± SD. *: p < 0.05.