UVSSA (UV stimulated scaffold protein A) is a critical adapter protein in transcription-coupled nucleotide excision repair (TC-NER), a pathway that rapidly removes RNA polymerase II-blocking DNA lesions from actively transcribed genes 1. UVSSA functions as a key scaffold that promotes recruitment of TC-NER factors, particularly facilitating ubiquitination of stalled RNA polymerase II (RNAPIIo) at damage sites, which triggers RNAPIIo backtracking and provides access for repair machinery 2. The protein recruits the TFIIH complex and stabilizes ERCC6/CSB by recruiting the deubiquitinating enzyme USP7, preventing proteasomal degradation of CSB 3. UVSSA possesses DNA and RNA binding regions through its N-terminal and C-terminal domains, enabling direct nucleic acid interactions during repair 4. Additionally, UVSSA positions STK19 between RNAPIIo and CSA to facilitate TFIIH positioning for lesion verification and downstream repair progression 56. Disease relevance is significant: mutations in UVSSA cause UV-sensitive syndrome (UVSS), characterized by UV hypersensitivity and defective TC-NER 3. Clinically, UVSSA differs from Cockayne syndrome proteins in lacking broader developmental impacts, with patients displaying primarily UV-related photosensitivity, underscoring UVSSA's specialized role in TC-NER without additional cellular functions.