HDAC9 and carotid atherosclerosis: Although very recent genome‐wide association studies have identified a variant in HDAC9 associated with large‐vessel ischaemic stroke 10 and further demonstrated that HDAC9 genetic variant associated with ischaemic stroke increases risk via promoting carotid atherosclerosis 11, the molecular mechanisms of HDAC9 in ischaemic stroke are still largely unclear.