ESR1 and breast carcinoma: As shown in Figure 1, FOXP3+ iTILs were an indicator of poor survival in ER − tumors, but a favorable prognostic indicator in ER − breast cancers, indicating that the interaction of FOXP3+ iTILs with ER status could mitigate the prognostic effect of FOXP3+ TILs in the unstratified breast cancer population.