Srrm4, also known as Serine/Arginine Repetitive Matrix Protein 4, is a neural-specific splicing factor. It is crucial for alternative splicing, especially of microexons which are important in neural differentiation and development. It has been found to regulate the splicing of genes like protrudin (Zfyve27), affecting neurite outgrowth [3].

Srrm4 is highly relevant in multiple diseases. In neuroendocrine prostate cancer (NEPC), its expression is strongly correlated with NEPC development and poor patient survival. High Srrm4 expression in castrate-resistant tumors is associated with NEPC markers and negatively correlated with adenocarcinoma markers. It may serve as a diagnosis and prognosis biomarker [1,4]. In breast cancer, overexpression of Srrm4 enhances brain-to-breast metastasis (BBM), while knockdown reduces proliferation and increases chemotherapy resistance [2]. In lung cancer, Srrm4 is highly expressed in small cell lung cancer (SCLC), and a gapmer antisense oligonucleotide targeting Srrm4 can lead to cell death and tumor reduction in a mouse model [5].

In conclusion, Srrm4 is a key regulator in alternative splicing, especially in neural-related processes. Its study through in vivo models has revealed its significant roles in cancer-related diseases such as prostate, breast, and lung cancers, highlighting its potential as a diagnostic, prognostic, and therapeutic target in these diseases.