Current Evidence Indicates That >95% of the CD4⁺CD8⁺ Double-Positive Thymocytes $\alpha$

question 32

Essay

Current evidence indicates that >95% of the CD4⁺CD8⁺ double-positive thymocytes generated will die in the thymus, and will never develop into mature CD4 or CD8 T cells. While a small proportion of these double-positive thymocytes may fail to produce a functional $\alpha$ : $\beta$ T-cell receptor, the majority of them do express a T-cell receptor complex on their surface. For any given double-positive thymocyte undergoing cell death in the thymus, what are the two possible explanations for its failure to mature?

---

Definitions:

Employee Wrongdoing

Actions by an employee that violate company policies or laws.

Serious Breach

A significant violation of a contractual agreement that results in substantial harm or allows the aggrieved party to terminate the contract.

Employment Contract

A legally binding agreement between an employer and an employee outlining the terms and conditions of employment.

Union Organization

A group formed by workers in various industries to collectively bargain for better wages, working conditions, and other employment rights.