Liu et al. assessed FOXP3+ TILs by immunohistochemistry on tissue microarrays constructed from a well-defined cohort of 3992 breast cancer patients and found that the prognostic value of FOXP3+ TILs in breast cancer differs depending on their ER and HER2 expression status and CD8+ T-cell infiltration32. The gene discussed is CD8A; the disease is breast cancer.