CD1D and hepatitis A virus infection: After the initial observation by Toyabe et al. suggesting the requirement of NKT cells for the development of ConA-induced hepatitis [42], the experiments by Kaneko et al. reported that NKT cells could be responsible for this hepatitis in RAG-deficient mice [43]; moreover, Takeda et al. showed that CD1d-deficient mice developed a markedly reduced disease compared to the wild-type mice [44].