While the numbers of white blood cells and lymphocytes decreased in patients with breast cancer, NK cytotoxicity and intracellular T‐cell signalling cytokines (IFN‐γ, IL‐4 and IL‐2) were higher at baseline comparing to healthy controls, and increased during and after 5‐fluorouracil, epirubicin and cyclophosphamide (FEC) treatment (Mozaffari et al., 2009). Here, IFNG is linked to breast cancer.