The suppression of tumor immunity by type I NKT cells in this model cannot be explained by the location of tumors within the liver, as therapeutic effects of α-GalCer treatment were shown in a B16 liver metastasis model [127] and liver CD4-CD8- NKT cells were reported to be highly potent inducers of anti-tumor immune responses among NKT cell subsets in spleens, livers, and thymus [128]. Here, CD4 is linked to neoplasm.