KAT2B and Down syndrome: At the same time, we investigated the binding mode to BAZ2A of chemical probes developed against the CECR2‐GCN5‐PCAF‐BPTF bromodomain subfamily I (Cat Eye syndrome chromosome region, candidate 2—general control non‐derepressible 5—p300/CREB binding protein associated factor—bromodomain and Plant HomeoDomain finger‐containing transcription factor) and of inhibitors of the p300/CBP bromodomains.