Comparisons among different potential HT biomarkers concluded that biomarkers related to the BBB (MMP‐9, tight‐junction proteins, S100‐β, glial fibrillary acidic protein [GFAP], NSE) should be the most promising predictors of symptomatic HT, as well as that inflammation indicators (leukocyte, C‐reactive protein, TNFα, IL‐6, IL‐10, vascular adhesion protein‐1 [VAP‐1]) would be a correct choice for predicting delayed HT.8 The gene discussed is TNF; the disease is hematocrit.