RNA polymerase II (Pol II) is an enzyme that is composed of twelve subunits and is responsible for the transcription of protein-coding genes. Transcription initiation requires Pol II-mediated recruitment of transcription machinery to a target promoter, thereby allowing transcription to begin. The integrator complex is a multi-protein complex that associates with the C-terminal domain of Pol II and is involved in small nuclear RNAs (snRNA) U1 and U2 transcription, specifically in their 3’-box-dependent processing. A component of the integrator complex, INTS5 (integrator complex subunit 5), also known as KIAA1698, is a 1019aa multi-pass membrane protein localized to the nucleus. The gene encoding INTS5 maps to human chromosome 11q12.3 and mouse chromosome 19 A.