The RBM15 gene encodes an RNA-binding protein that plays a crucial role in various cellular processes, particularly those related to RNA methylation, splicing, and gene regulation. Here’s a detailed overview based on the requests:

### 1. Associated Genes
While the summaries mainly focus on RBM15’s functions, it is potentially associated with several other genes directly or indirectly involved in similar processes. Some of these include:
- **YTHDC1**: This gene, which encodes an m6A RNA binding protein, is involved in the transcriptional regulation of m6A-modified RNAs. It is noted in the context of X chromosome inactivation mediated by Xist RNA.
- **MPL (myeloproliferative leukemia virus oncogene)**: Involved in thrombopoiesis, RBM15 regulates the splicing of this gene and is thus associated with hematopoietic processes.
- **HOX Genes**: While not explicitly stated in the summaries, evidence suggests RBM15 may have roles in regulating the expression of HOX genes, which are important in development and cellular identity.

### 2. Aging and Age-Related Diseases
Information relating RBM15 to aging or age-related diseases is limited, but its roles in:
- **Stem cell maintenance**: RBM15’s involvement in the homeostasis of long-term hematopoietic stem cells may connect it to aging, as stem cell function typically declines with age.
- **Blood cell differentiation**: Dysregulation of mechanisms involving RBM15 could potentially lead to hematological disorders, which may become more prevalent with age.
- **X chromosome inactivation**: Alterations in X-linked gene expression due to malfunctions in Xist RNA, mediated by RBM15, may have implications in age-related diseases, particularly in females.

### 3. Drug Interactions
As of my last update, there are no known specific drug interactions explicitly documented for RBM15. However, because it is involved in RNA methylation and splicing, drugs that target epigenetic modifications (e.g., methyltransferase inhibitors or splicing modulators) may indirectly influence processes mediated by RBM15. Any further searches in clinical databases or publications could provide insights into emerging drugs targeting the pathways associated with this gene.

### 4. Pathways and Biological Processes
RBM15 is involved in several critical biological processes and pathways, including:
- **N6-methyladenosine (m6A) modification**: Mediates pre-mRNA methylation, influencing RNA stability, splicing efficiency, and translation.
- **Hematopoiesis**: Plays a role in the differentiation of megakaryocytes and B-cells, and in the maintenance of hematopoietic stem cells.
- **X chromosome inactivation**: Functions in promoting transcriptional repression through the recruitment of the m6A methylation complex associated with Xist RNA.
- **Developmental processes**: Important for embryonic development, especially in heart and spleen formation, as well as placental vascular morphogenesis.

In conclusion, the RBM15 gene is a multifaceted component of cellular regulation, closely tied to processes vital for development, hematopoiesis, and epigenetic modifications like m6A methylation. Further research may elucidate additional associations with age-related mechanisms and potential pharmacological targets.