NAP1L4 (nucleosome assembly protein 1 like 4) is a histone chaperone protein that mediates nucleosome assembly and chr11 remodeling 1. The protein contains N- and C-terminal domains required for histone binding and transfer onto DNA, and shuttles between the cytoplasm and nucleus to facilitate its chaperone functions 1. Beyond chr11 assembly, NAP1L4 plays regulatory roles in cellular stress responses by modulating p53 acetylation at specific lysine residues (Lys320 and Lys382), thereby controlling the expression of p53-responsive genes involved in cell cycle arrest and apoptosis 2. During viral infection, NAP1L4 interacts with Chikungunya virus nonstructural protein 3 (nsP3) in a phosphorylation-dependent manner to promote viral replication complex assembly 3. In disease contexts, NAP1L4 dysregulation is implicated in pulmonary hypertension, where a circular RNA derived from NAP1L4 regulates glycolysis-associated gene expression through super-enhancer mechanisms in pulmonary artery smooth muscle cells 4. Genomically, NAP1L4 resides within the KCNQ1 imprinted domain on chromosome 11, though its imprinting status differs between species: humans and cattle show biallelic expression 56, while pigs show tissue-specific imprinting patterns 7. These multifaceted functions position NAP1L4 as an important regulator of chr11 dynamics, cellular stress responses, and disease pathology.