Therefore, we hypothesised that ICAM2 inhibitors could enhance the effect of radiation on cancer cells that constitutively express ICAM2. Small-interfering RNA has been used widely to silence gene expression and has been evaluated as an attractive tool for use in therapeutics of many cancers (Gao et al, 2005; Zhang et al, 2005; Amarzguioui et al, 2006; Halder et al, 2006; Hosaka et al, 2006). Here, ICAM2 is linked to cancer.