Figure 5. PKR promotes tube formation of RF/6A cells in a coculture system under hypoxic conditions. A: Microscopic images showing tube formation in each group: normal, hypoxic, scramble siRNA, and dsRNA-activated protein kinase (PKR) siRNA. Representative photographs of tube formation of RF/6A cells (200× magnification). B: Decreased tube formation was observed when the cocultured RF/6A cells were transfected with PKR siRNA under hypoxia. *p<0.01, PKR siRNA group versus the hypoxia group. Values represent means ± SD.