### PPIAL4D Gene Overview

**Gene Symbol:** PPIAL4D  
**Predicted Functions:** 
- Cyclosporin A binding activity
- Peptidyl-prolyl cis-trans isomerase activity  
**Predicted Involvement:** 
- Protein folding 
- Protein peptidyl-prolyl isomerization  
**Predicted Location:** 
- Cytoplasm 
- Intracellular membrane-bounded organelles  
**Protein Summary:** 
PPIases, such as PPIAL4D, are essential for accelerating protein folding. They specifically catalyze the cis-trans isomerization of proline imidic peptide bonds within oligopeptides, facilitating proper protein structure formation.

### 1. Associated Genes
PPIAL4D may have interactions or associations with other genes involved in similar protein folding pathways or functions, specifically:

- **PPIA (Peptidylprolyl isomerase A):** Another well-known PPIase involved in protein folding.
- **FKBP Family Members (FKBP1A, FKBP1B):** Members of the immunophilin family that also participate in the folding and trafficking of proteins.
- **CHP (Calcineurin Homologous Protein):** Could be associated due to its role in protein folding.
  
These associations can stem from co-expression data or shared involvement in signaling pathways.

### 2. Aging and Age-Related Diseases
While specific studies directly linking PPIAL4D to aging or age-related diseases are limited, the following considerations apply:

- **Protein Misfolding Diseases:** Since PPIAL4D facilitates protein folding, deficiencies or dysregulation may contribute to protein misfolding diseases, which are known to increase in prevalence with age (e.g. Alzheimer's disease).
- **Stress Response:** The role of PPIases in cellular responses to stress may be important in aging contexts, as misfolded proteins and cellular stress are common features in aged cells.

Research literature can sometimes yield findings that connect PPIAL4D expression levels with age-related cellular processes or biomarkers, suggesting a role in longevity and healthspan.

### 3. Drug Interactions
- **Cyclosporin A:** Given its predicted binding activity, this immunosuppressive drug interacts with PPIAL4D. Cyclosporin A is known to inhibit the activity of various PPIases.
- **Rapamycin:** While primarily a mechanistic target of rapamycin (mTOR) inhibitor, there may be indirect effects on PPIases considering alterations in protein folding dynamics.
  
Additional drugs that target similar pathways involving PPIases may also interact or hold relevance, particularly in the context of immunosuppression and anti-cancer therapies.

### 4. Pathways and Biological Processes
PPIAL4D is implicated in several biological pathways and processes such as:

- **Protein Folding Pathway:** Central to its function in assisting proper protein conformation.
- **Cytosolic Protein Folding:** Directly involved in the maintenance of protein homeostasis within the cytoplasm.
- **Intracellular Signaling Cascades:** May play a role in pathways influenced by stress responses or cellular signaling that impacts protein stability.

### Summary
The PPIAL4D gene encodes a peptidyl-prolyl isomerase that facilitates protein folding, and has potential links to aging, age-related diseases, and drug interactions primarily through its relation to cyclosporin A. Ongoing research in the field could reveal more intricate relationships in health and disease mechanisms involving PPIAL4D.