What are the three class I gene products?

The three class I gene products are indeed HLA-A, HLA-B, and HLA-C. These molecules are part of the major histocompatibility complex (MHC) class I and play a crucial role in the immune system by presenting peptides from intracellular proteins to CD8+ T cells. This presentation is vital for the recognition of infected or malignant cells by the immune system, as it helps alert T cells to the presence of these abnormalities.

HLA-A, HLA-B, and HLA-C are highly polymorphic, meaning that there are many different variants of these genes in the human population, which contributes to the diversity of the immune response. Additionally, their expression on nearly all nucleated cells allows for a broad range of surveillance against pathogens and helps in distinguishing self from non-self, which is essential for preventing autoimmune diseases and ensuring transplant compatibility.

The other options listed refer to different aspects of the immune system, such as class II gene products or various co-stimulatory molecules, but they do not represent class I MHC molecules. For example, HLA-DP, HLA-DQ, and HLA-DR are class II gene products involved in presenting antigens to CD4+ T cells, while CD4,