JADE1 is a scaffold subunit that directs the specificity and enzymatic activity of the HBO1 histone acetyltransferase complex. Through its PHD (Plant Homeo-domain) zinc finger regions, JADE1 physically links the catalytic HBO1 subunit with nucleosomal histone H3-H4, increasing the catalytic efficiency of H4 acetylation at residues K5, K8, and K12 1. Beyond acetylation, JADE1 also promotes HBO1-mediated lysine lactylation and propionylation on histones, enhancing gene transcription at promoters and transcription start sites 2. JADE1 regulates DNA replication initiation and cell cycle progression through these histone modifications. Recent evidence suggests JADE1 plays unexpected roles in disease: genome-wide association studies in primary age-related tauopathy identified a JADE1 locus associated with neurofibrillary tangle burden, and JADE1 physically interacts with tau protein in affected neurons 3. Additionally, JADE1 functions as a renal tumor suppressor by stabilizing through pVHL interaction and promoting degradation of β-catenin to inhibit canonical Wnt signaling 4. A gene trap mutation in mice produces a null allele; however, homozygotes are viable and fertile, suggesting functional redundancy with other JADE family members 5.