Impact of cytokine release from HOXB9 overexpressed cells on angiogenesis and cell proliferation. (a) Cancer cells (3000 cells/well) were seeded on micropore membrane over 24-wells plate and incubated for 24 h before tetracycline administration and/or co-culture with HUVECs and HDFs. After 48 hours incubation with tetracycline and/or co-culture system, the number of cancer cells were counted (n = 8, each). (b) Total capillary length of co-cultured HUVECs were evaluated in immunohistochemical staining of CD31 after 48 hours incubation with HOXB9 induced cell lines (n = 8, each). Error bars are SDs. ☆p < 0.05 by the U-test.