### METTL18 Gene Overview

**Gene Symbol:** METTL18  
**Function:** METTL18 is a protein-L-histidine N-tele-methyltransferase that specifically monomethylates ribosomal protein RPL3, playing a crucial role in the regulation of translation elongation and the prevention of the aggregation of tyrosine-rich proteins. 

**Location:** This gene is located in the cytosol and nucleolus and is part of a protein-containing complex.

### 1. Associated Genes
While the summaries provided do not list specific associated genes, METTL18 is functionally linked to:

- **RPL3 (Ribosomal Protein L3):** The primary target of METTL18, crucial for ribosomal assembly and translation.
- **Other ribosomal protein genes (RPS and RPL family members)** may also be indirectly associated due to its role in ribosome biogenesis and function. 

### 2. Aging and Age-Related Diseases
While there are limited studies directly linking METTL18 to aging or age-related diseases, there are implications based on its role in translation regulation:

- **Protein Synthesis:** Impairments in protein synthesis and ribosome function have been associated with age-related decline in cellular function. Alterations in METTL18 function could contribute to this decline.
- **Neurodegenerative Diseases:** Given its role in protein folding and prevention of aggregation, dysregulation of METTL18 could play a role in conditions characterized by protein misfolding, such as Alzheimer's and Parkinson's diseases.

### 3. Drug and Drug Classes
Current literature does not provide specific drugs or drug classes that directly interact with METTL18. However, general activity of histone methylation and protein modifications may be influenced by:

- **Histone Methylation Inhibitors:** Compounds like small molecule inhibitors that target methyltransferases could indirectly affect METTL18 activity through global changes in methylation patterns.
- **Others in Translation Regulation:** Drugs targeting translation or ribosome biogenesis could have downstream effects on ITOTHL18 activity.

### 4. Pathways and Biological Processes
METTL18 is involved in crucial biological processes:

- **Translation Elongation:** Its specific action on RPL3 points to a defined role in the regulation of protein synthesis.
- **Regulation of Gene Expression:** By modifying ribosomal proteins, METTL18 may impact the expression of various genes dependent on proper translation dynamics.
- **Ribosome Biogenesis:** It is part of the larger framework that assembles functional ribosomal subunits critical for protein synthesis.

### Summary
METTL18 plays an essential role in the fine-tuning of translation through histidine methylation, impacting cellular homeostasis and potentially the aging process. Further research may reveal more about its potential associations with aging, drug interactions, and its broader implications in health and disease.