ARL6IP4 (ARF like GTPase 6 interacting protein 4) is a nuclear protein involved in modulating alternative pre-mRNA splicing. It contains serine-arginine (SR) repeat domains and multiple nuclear localization signals, characteristics shared with other splicing regulatory proteins 1. The protein can facilitate either 5' distal site activation or preferential use of 3' proximal sites during alternative splicing, and may act as a splicing inhibitor of Herpes simplex virus pre-mRNA during viral infection [UniProt]. Recent evidence demonstrates that ARL6IP4 undergoes liquid-liquid phase separation (LLPS) in live cells, suggesting a role in forming biomolecular condensates that may regulate splicing machinery assembly 2. ARL6IP4 is upregulated in multiple cancer types: it was identified as a fatty acid metabolism-related biomarker associated with clear cell renal cell carcinoma progression 3 and as part of an eight-gene LLPS-related prognostic signature in colorectal cancer 2. In neurological contexts, ARL6IP4 variants associate with schizophrenia susceptibility through effects on methylation and splicing patterns 45, and ARL6IP4-derived proteoforms are implicated in pre-mRNA splicing regulation during Alzheimer's disease pathogenesis 6. Additionally, ARL6IP4 participates in Rac1 signaling pathways relevant to apoptosis regulation in melanoma 7.