ICE1 (interactor of little elongation complex ELL subunit 1) serves as a scaffold protein essential for small nuclear RNA (snRNA) gene transcription regulation. ICE1 is a core component of the little elongation complex (LEC), where it promotes complex formation and facilitates RNA polymerase II recruitment and occupancy at snRNA genes within subnuclear bodies 1. The protein's transcriptional regulatory function is subject to tumor suppressor p53 control, which inhibits the interaction between ELL/EAF and ICE1, thereby repressing snRNA gene transcription by RNA polymerase II 2. Beyond transcriptional regulation, ICE1 participates in post-transcriptional processes through the nonsense-mediated mRNA decay (NMD) pathway, where it uses a putative MIF4G domain to interact with exon junction complex proteins and promotes UPF3B association with the EJC, enhancing detection of aberrant transcripts containing premature termination codons 3. Clinically, ICE1 deletions are associated with Cri-du-Chat syndrome features including the characteristic cat-like cry, with comparative analysis narrowing the critical region for this phenotype to less than 1 Mb encompassing ICE1 1. Additionally, ICE1 shows relevance in cancer chemoresistance, where its upregulation via the SVIL-AS1/miR-103a/ICE1 axis enhances DNA damage response to chemotherapeutic agents 4.