Which feature is NOT associated with MHC class I molecules?

MHC class I molecules are primarily responsible for presenting intracellular antigens, which are typically derived from proteins produced within the cell, including those from viruses that have infected the cell. These molecules are recognized by CD8+ T cells, whose role is to destroy cells displaying foreign or abnormal peptides, such as those produced during a viral infection.

When considering the characteristic that is not associated with MHC class I molecules, it is crucial to understand that they present endogenous antigens, rather than extracellular ones. Extracellular antigens are typically presented on MHC class II molecules, which are recognized by CD4+ T cells. This distinction is fundamental to the understanding of the immune response and the roles that different MHC classes play in recognizing and responding to various types of pathogens.

Therefore, the assertion that MHC class I molecules present extracellular antigens clearly distinguishes it as the correct choice in this context, as it highlights the specialized function of MHC class I in immune surveillance of intracellular pathogens.