Although we only focused on the expression of Th1- and Treg-associated chemokine genes and the infiltration of CD4+, CD8+, and Foxp3+ cells in 4NQO-induced mouse tongue tumorigenesis, other immune cells, including myeloid-derived suppressor cells [37], eosinophils [38], Th17 cells [23], tumor-associated macrophages [39], and the chemokines responsible for the infiltration of these cells also reportedly participate in tumorigenesis. Here, CD4 is linked to neoplasm.