SREK1 (splicing regulatory glutamic acid and lysine rich protein 1) is an RNA-binding protein that regulates alternative splicing by modulating the activity of other splicing factors 1. The protein functions as a regulator of pre-mRNA splicing, with TAF1 identified as one of its targets 1. SREK1 localizes to nuclear speckles, consistent with its role in RNA processing 1. The protein exists in multiple isoforms, including an exon 10-inclusive variant (SREK1L) that acts as an oncogenic driver in hepatocellular carcinoma by sustaining BLOC1S5-TXNDC5 expression and forming regulatory loops with SRSF10 2. SREK1 dysfunction contributes to neurological disease pathogenesis, as decreased SREK1 levels in Huntington's disease lead to reduced TAF1 expression and striatal atrophy, while SREK1 overexpression corrects these defects 1. The protein shows altered expression in various pathological conditions, being upregulated in preeclampsia serum 3 and identified as a potential biomarker in COPD and lung cancer through network analysis 4. Genetic variants in SREK1, such as rs74794265, may influence disease susceptibility, with the C/T genotype appearing protective against COPD in certain populations 5.