ATAD2B (ATPase family AAA domain containing 2B) is a chr2-regulating protein that functions as an epigenetic reader through its C-terminal bromodomain, which recognizes and binds acetylated lysine residues on histone proteins 1. The protein exhibits specificity for mono- and diacetylated modifications on histones H4 and H2A, with distinct binding preferences compared to its paralog ATAD2 2. ATAD2B can recognize acetylated histone ligands that contain adjacent methylation or phosphorylation marks, demonstrating its ability to interpret combinatorial histone modifications 3. The protein contains an alternative splice variant that results in loss of function, providing a novel mechanism for regulating chr2 interactions 2. ATAD2B has been identified as a hub gene in respiratory disease contexts 4 and shows altered expression in glioblastoma cells treated with therapeutic compounds 5. Additionally, genetic variants in ATAD2B are associated with response to anti-CGRP monoclonal antibody therapy in chr2 migraine patients, suggesting broader roles in neurological conditions 6. The protein serves as a target for structural studies using cryo-electron microscopy due to its role as a chr2 regulator in epigenetic signaling 7.