Preclinical studies have explored the role of CCR8 and have demonstrated that, although CCR8 serves as a marker of highly suppressive intratumoral Tregs, CCR8 knock-out mouse models do not exhibit impaired tumor Treg infiltration or a diminished immunosuppressive function suggesting that CCR8 is not essential for Treg trafficking but rather identifies a subset of activated and tumor-resident Tregs [146]. This evidence concerns the gene CCR8 and neoplasm.