SNRNP40 is a core component of the U5 small nuclear ribonucleoprotein (snRNP) complex and the U4/U6-U5 tri-snRNP complex, which are essential building blocks of the spliceosome 12. As part of the activated spliceosome, SNRNP40 is required for pre-mRNA splicing through transesterification reactions 34. The protein participates in spliceosomal conformational changes and likely contributes to minor spliceosome function involving U12-type intron splicing. Clinically, SNRNP40 dysregulation is implicated in cancer progression. Low SNRNP40 expression promotes metastatic colonization in breast cancer and is associated with metastatic relapse 5. Additionally, SNRNP40 variants and altered expression have been identified in acute leukemia stemness networks 6, pancreatic cancer-associated stellate cells 7, and non-muscle invasive bladder cancer 8. A maternal genetic variant in SNRNP40 is associated with preterm prelabor rupture of membranes 9. While SNRNP40 mutations occur in U5 snRNP-related disorders, the mechanisms underlying tissue-specific disease phenotypes remain unclear 10, representing an important area for future investigation.