IR-induced NF-κB mediates HER2 overexpression in the radioresistant breast cancer cells selected from FIR-derived heterogenic population (Cao et al. 2009), indicating that not only HER2 can induce NF-κB activity upon IR but also NF-κB can induce the overexpression of HER2. This evidence concerns the gene NFKB1 and breast carcinoma.