For example, in experimental tumour models, the growth of methylcholanthrene (MCA)-induced sarcoma cell lines is restricted by physiological IFNγ produced by endogenous NKT cells [18], while many other experimental cell lines, including the B16-F10 melanoma are only controlled by NKT cells following therapeutic activation with α-GalCer, again in an IFNγ-dependent manner [7]. This evidence concerns the gene IFNG and sarcoma.