This finding is significant as it extends the utility of the WBC/Hb ratio beyond earlier research [27], which primarily focused on specific groups like those with pulmonary hypertension or heart failure, and reported AUC values between 0.646 and 0.751 for the WBC/Hb ratio in predicting 30-day mortality [28]. The gene discussed is GSTM1; the disease is pulmonary arterial hypertension.