Interestingly, another chemokine receptor, CCR8, has recently been identified as a marker that is specifically expressed in at least a subset of tumor-infiltrating Treg, but not Treg in the periphery, as part of a tumor-infiltrating Treg transcriptional signature that is conserved across species and tumor types (Plitas et al., 2016; De Simone et al., 2016; Zheng et al., 2017; Magnuson et al., 2018) (Figure 1). Here, CCR8 is linked to neoplasm.