The letter to the editor was written in response to "Plasma interleukin-6 is a potential predictive biomarker for postoperative delirium (POD) among acute type a aortic dissection patients treated with open surgical repair", which is recently published by Lv et al. (J Cardiothorac Surg 16(1):146, 2021). Here, IL6 is linked to delirium.