However, frequency of regulatory T cells (Treg, Foxp3+CD4+ T) was reduced in the tumor of Eomesfl/flCd4Cre mice (Figure S3B), suggesting that Eomes might play a role in development or maintenance of intra-tumoral Treg cells instead of regulating effector functions of CD4+ T cells. Here, FOXP3 is linked to neoplasm.