Multiple cytokines, such as IL-6, IL-8 and IL-4, have been shown to be expressed at higher levels after cancer treatment (for example radiation and chemotherapy (docetaxel)), and may play a crucial role in resistance mechanisms.15, 20, 29 In order to verify whether IL-4 may influence the recovery potential of primary cancer cells after irradiation, clonogenic recovery assays were performed after cells were exposed to increasing doses of γ-irradiation (2.5, 5, and 10 Gy) in the presence or absence of IL-4. This evidence concerns the gene IL6 and cancer.