In this review, we will outline the advantages of harnessing iNKT cells particularly for adoptive immunotherapy, also when compared to conventional αβ T cells, given that they: (i) Control the tumor microenvironment (TME); (ii) Can be redirected against cancer cells by engineering with a tumor-specific CAR or TCR while maintaining their intrinsic control of the TME; (iii) Are devoid of alloreactivity, being restricted for the monomorphic CD1d molecule, allowing their possible use off the shelf in a donor-unrestricted manner. This evidence concerns the gene CD1D and neoplasm.