No association was found between PbtO2-levels and poor functional outcome after 3 and 6 months (adjOR 0.98/mmHg, 95% CI 0.94–1.02, p = 0.32) independently of established outcome parameters (WFNS grade, loss of consciousness, age, and anemia, Hb < 9 g/dL) in 95 patients. The gene discussed is GSTM1; the disease is anemia (phenotype).