CLASRP (CLK4 associating serine/arginine rich protein) is an alternative splicing regulator that functions as a nucleoplasmic protein binding factor. It likely regulates mRNA splicing of genes including CLK1 through interaction with the CLK kinase family 1. Mechanistically, CLASRP modulates RNA splicing patterns, a process increasingly implicated in disease pathogenesis. In multiple myeloma, CLASRP was identified as a differentially spliced gene associated with abnormal splicing patterns, with high numbers of novel splice variants correlating with adverse survival and ultra-high risk classification 2. In prostate cancer, CLASRP was identified as a hub gene in drug resistance-related modules primarily involved in RNA splicing pathways, suggesting its role in endocrine therapy resistance mechanisms 3. Clinically, CLASRP shows oncogenic activity in colorectal cancer, where elevated expression correlates with metastasis. CLASRP overexpression promotes cancer cell proliferation, migration, and invasion in vitro and tumor growth in vivo 1. These effects are reversible through CLK inhibitor treatment, which induces apoptosis via caspase pathway activation, identifying CLASRP-CLK signaling as a potential therapeutic target 1. Additionally, CLASRP methylation status associates with orofacial cleft susceptibility 4, suggesting broader epigenetic involvement in developmental disease.