Although the role of TILs in the prognosis of cancer is controversial, a large body of literature supports that TILs are strongly associated with recurrence rates and survival in multiple solid tumors.5 Similar correlations are reported in BC, although the magnitude of the effect varies by disease subtype, and high levels of TILs are mostly evident in estrogen receptor (ER)‐negative and human epidermal growth factor receptor 2 (HER2)‐positive subtypes. The gene discussed is ESR1; the disease is cancer.