Their data suggest that the levels of activated CD8+ T cells might predict which DCIS is likely to progress to invasive disease.82 In patients with invasive breast cancer – particularly those with triple-negative and HER2-positive subtypes – the presence of tumour-infiltrating lymphocytes (TILs), especially higher numbers of CD8+ cells, together with fewer FOXP3+ regulatory T cells, is associated with a better outcome.83 This evidence concerns the gene CD8A and ductal breast carcinoma in situ.