INTS15 is a subunit of the integrator complex, a multiprotein machine that terminates RNA polymerase II (Pol II) transcription in the promoter-proximal region of genes 1. Within the integrator complex, INTS15 is part of the tail module that acts as a platform for transcription factor recruitment and bridges different integrator modules 23. The integrator complex executes transcription termination through three mechanisms: dephosphorylation of Pol II and associated factors, endonucleolytic degradation of nascent RNA, and promotion of Pol II release from DNA 1. INTS15 supports termination of both coding and non-coding Pol II transcripts, including snRNAs, enhancer RNAs, and lncRNAs 1. Beyond transcription termination, INTS15 controls snRNA 3' end processing, which indirectly regulates mRNA splicing 4. Clinically, mutations in INTS15 cause variable panocular malformations (VPMs), an autosomal-dominant eye disease, with homozygous knockout mice showing embryonic lethality 4. INTS15 is particularly critical for eye and brain development, supporting axonal outgrowth in retinal ganglion cells 4. Additionally, INTS15 regulates cell cycle progression through p53/p21 signaling and promotes differentiation of induced pluripotent stem cells into germ layers and retinal tissues 5.