### KIR3DL2 Gene Overview

**Gene Symbol:** KIR3DL2  
**Location:** Chromosome 19q13.4 (leukocyte receptor complex)

KIR3DL2 encodes a transmembrane glycoprotein that is a member of the killer immunoglobulin-like receptor (KIR) family, which plays a critical role in the immune system by regulating the activity of natural killer (NK) cells and some T cell subsets. It interacts with specific MHC class I molecules, particularly HLA class I proteins, to modulate immune responses. Importantly, KIR3DL2 negatively regulates NK and T cell effector functions when it binds to its ligand, the peptide-free HLA-F open conformer.

### 1. Associated Genes
Other genes that are often associated with KIR3DL2 due to proximity on the KIR gene cluster or functional interactions include:
- KIR3DL1
- KIR3DL3
- KIR3DP1
- KIR3DL4
- KIR2DL1 to 3 (different family members involved in MHC class I recognition)
- HLA-F (ligand for KIR3DL2)

### 2. Aging and Age-Related Diseases
While specific studies on KIR3DL2’s direct association with aging or age-related diseases are limited, KIR genes in general, including KIR3DL2, have been implicated in several conditions which may have an age-related component. Alterations in KIR profiles can influence susceptibility to infections, autoimmune diseases, and cancers, all of which may have heightened prevalence in older populations. It has also been observed that KIR gene expression can vary with age, affecting immune response capabilities.

### 3. Drug Interactions
There are currently no well-defined drugs or drug classes specifically known to interact directly with KIR3DL2. However, because KIR proteins play roles in immune signaling, compounds that modulate immune responses, including monoclonal antibodies targeting immune checkpoints (e.g., PD-1/PD-L1 inhibitors), may indirectly influence KIR3DL2 mediated pathways in a therapeutic context. Drugs affecting NK cell activity or involved in immunotherapy are particularly relevant.

### 4. Pathways and Biological Processes
KIR3DL2 is involved in several important biological processes and pathways:

- **Immune Response Regulation:** KIR3DL2 modulates the activity of NK cells and T cells, directly influencing immune evasion by tumors or virally infected cells.
- **Signal Transduction:** KIR3DL2 participates in signaling pathways upon ligand binding, leading to inhibitory or regulatory signals in immune responses. This includes activation of transcription factors involved in downstream signaling cascades.
- **Interaction with HLA Class I Antigens:** The binding of KIR3DL2 to HLA-F plays a role in inhibiting cytotoxic responses of NK and T cells, which is crucial in maintaining self-tolerance and modulating immune responses against tumors and infected cells.
- **Astrocyte Interaction:** KIR3DL2 has been shown to act as a receptor on astrocytes, suggesting potential roles in neuroimmunology and neuroprotection.

In summary, KIR3DL2 is a critical receptor involved in the regulation of immune responses, particularly within the context of NK cell function and interactions with HLA class I molecules, with potential implications in aging and age-related diseases as well as pathways regulating immune tolerance and responses.