Mucosal-associated invariant T cell
Mucosal-associated invariant T cells (MAIT cells) make up a subset of T cells in the immune system that display innate, effector-like qualities. In humans, MAIT cells are found in the blood, liver, lungs, and mucosa, defending against microbial activity and infection.
Source: Wikipedia — Mucosal-associated invariant T cell (CC BY-SA 4.0)