No correlation could be found between a patient’s age at the time of trauma and PER2 and HO-1 expression (PER2: r = 0.012, P = 0.935, r2 = 0.005, P = 0.634; HO1: r = 0.002, P = 0.988, r2 = 0.029, P = 0.247, Fig. 4e), suggesting an age-independent correlation between these gene expression patterns and delirium. The gene discussed is HMOX1; the disease is delirium.