T-cell receptor

 T-cell receptors (also known as TCRs) are an incredibly important part of immunology.

One of their key characteristics is their diversity, allowing for recognition of many different antigens. 

Similar to B cells, they are produced in the bone marrow, however differentiate in the thymus by breaking and rearranging their genes (whereas B cells differentiate in the bone marrow).

Their variable regions are encoded by V, D and J segments, which can arrange in any format, which is what allows them to be so diverse.