The **MIR371B** gene encodes a microRNA (miRNA) that plays an essential role in regulating gene expression post-transcriptionally. Below is a detailed description responding to your requests:

### 1. Associated Genes
MIR371B is part of the **MIR371/372/373** cluster located on chromosome 19, which includes the following associated genes:
- **MIR371**: Typically involved in similar regulatory functions as MIR371B.
- **MIR372**: Also plays a role in the regulatory networks of various genes.
- **MIR373**: Related to the stress response, apoptosis, and cancer pathways.

In addition to these miRNAs, MIR371B may interact with numerous target genes implicated in various cellular processes, particularly in tumorigenesis and development.

### 2. Age-Related Details
Research indicates that miRNAs, including MIR371B, are involved in the regulation of cellular processes that can influence aging and age-related diseases. While specific studies directly linking MIR371B to aging are limited, miRNAs have been shown to modulate:
- **Cellular senescence**: Alterations in miRNA expression can impact the senescence pathways of cells.
- **Stem cell function**: Influence over pluripotency and self-renewal traits.
- **Age-related disorders**: Involved in the modulation of age-related diseases such as cancer and neurodegeneration.

### 3. Drug Interactions
Currently, there is no specific information available regarding drugs or drug classes that directly interact with the MIR371B gene itself. However, miRNAs are known to modulate the response to certain therapeutics, particularly in the realm of cancer treatment. Compounds that modulate miRNA expression, either through miRNA mimics or inhibitors, may have indirect effects on the regulatory activities of MIR371B. Research in developing miRNA-based therapeutics is ongoing, which may eventually link this miRNA with specific drugs.

### 4. Pathways and Biological Processes
MIR371B is involved in various biological pathways, reflecting its role as a regulatory molecule. Some of these include:
- **Cell cycle regulation**: Targeting genes responsible for cell proliferation.
- **Apoptosis**: Involvement in programmed cell death as part of the developmental processes or stress responses.
- **Development**: miRNAs are crucial during early developmental stages, affecting differentiation and morphogenesis.
- **Cancer development**: Expression levels of MIR371B have been linked to oncogenesis and metastasis in several cancer types, indicating its regulatory role in tumor biology.

Overall, MIR371B and its associated pathways highlight the complexity of gene regulation via miRNAs, with implications in normal biological processes as well as disease mechanisms. Further research is pivotal to elucidate its exact functions and therapeutic potentials.