The infiltration of CD8+ T-cells is associated with better prognosis in ER– and ER+/HER2+ tumours, but no association was found in ER+ tumours (Baker et al. 2011, Mahmoud et al. 2011, West et al. 2011, Liu et al. 2012, Seo et al. 2013, Ali et al. 2014, Chen et al. 2014, Gallego-Ortega et al. 2015). This evidence concerns the gene CD8A and neoplasm.