It was also demonstrated that CD49b+ CD3+ natural killer T (NKT) cells increased in the liver after a primary infection with P. yoelii non-lethal strain (17XNL), and that CD1d-restricted NKT cells, which secrete IFNγ, are critical to reduce liver-stage burden in a secondary infection (Miller et al., 2014). The gene discussed is CD1D; the disease is infection.