In the systematic review by Shobeiri et al. (2022), which aimed to summarize the existing evidence assessing BDNF serum and plasma levels in patients with ischemic heart disease and included nine cross-sectional studies, the authors demonstrated, after the exclusion of two outliers, that BDNF levels were significantly lower in patients with ischemic heart disease than in healthy patients (SMD = −0.57, 95% CI: −1.18; 0.04, p-value = 0.068, I2= 97.2%, p < 0.0001). The gene discussed is BDNF; the disease is coronary artery disorder.