Which CD marker is found on NKT cells but absent on NK cells?

NKT cells, or Natural Killer T cells, are a unique subset of T cells that share properties of both T cells and natural killer (NK) cells. One of the defining characteristics of NKT cells is the presence of the CD3 marker, which is involved in T cell receptor signaling. This marker is crucial for the activation and function of NKT cells, as it indicates that they are part of the T cell lineage.

In contrast, NK cells do not express CD3, and instead, they possess a different set of markers that are characteristic of the innate immune response. The presence of CD3 on NKT cells but not on NK cells highlights their role in the adaptive immune response and distinguishes them from the more traditional NK cells.

The other markers listed have different patterns of expression among these cell types. For example, CD16 is expressed on NK cells and has a role in antibody-dependent cellular cytotoxicity, while CD56 is also primarily associated with NK cells. CD4 is another marker that is found on helper T cells, and while some subsets of NKT cells may express CD4, it is not universally present on all NKT cells nor is it absent on all NK cells. Thus, CD3 is specifically associated with NKT