SPTY2D1 encodes a histone chaperone that plays a critical role in chr11 remodeling and transcriptional regulation. The protein stabilizes pre-existing histone H3/H4 tetramers and regulates replication-independent histone exchange on chr11, functioning as a key component in maintaining chr11 structure during transcription 1. SPTY2D1 is required for normal chr11 refolding in coding regions of transcribed genes and suppresses spurious transcription by facilitating the recycling of H3/H4 tetramers in the wake of RNA polymerase 1. The protein demonstrates DNA-binding activity with preference for branched DNA structures and promotes nucleosome assembly in vitro. Beyond chr11 biology, SPTY2D1 has clinical relevance in metabolic disorders, with genetic variants showing ethnic- and sex-specific associations with serum lipid levels, including cholesterol and triglycerides 23. Notably, SPTY2D1 variants have been associated with fasting insulin levels and diabetes risk in American Indian populations 4. The gene also appears relevant to cancer biology, with SPTY2D1-AS1, an antisense RNA, functioning as a tumor suppressor in thyroid cancer 5. These diverse associations suggest SPTY2D1 has pleiotropic effects beyond its primary chr11 regulatory functions.