RNU4-1: RNU4-1 is a small nuclear RNA (snRNA) that has been found to be significantly present in the regulatory network of several genes, including survival-associated AS events and splicing factors [PMC9519915] [PMC7272712]. It has been observed that RNApol2 is significantly decreased at unexpected sites, such as CEBPB, and many snRNAs, including RNU4-1 [PMC6166801]. RNU4-1 has also been found to have extreme differential co-expression values with mRNA encoding ribosomal proteins and other small nuclear RNAs [PMC7236799]. However, RNU4-1 was not found in the training cohort of a study that identified several splicing factors [PMC9467413]. It has also been shown that overexpression of RPS10P2-AS1 increases the expression of RNU4-1 and other small nuclear RNAs involved in ribosomal function [PMC6804435]. In endometrial cancer, RNU4-1 has been linked to patient outcome-associated alternative splicing [PMC9803687]. Additionally, RNU4-1 has shown upregulation in higher grade tumors and tumors with receptor negative status in breast cancer patients [PMC9803687]. However, no information about the involvement of RNU4-1 in breast or other cancers was found in PubMed or the NURSA Transcriptomine database [PMC5966448]. Finally, INTS11 depletion leads to an accumulation of unprocessed RNU4-1 precursors as expected [PMC7610016].