The mean of Hp concentration was 1.97 ± 0.99 mg/ml (mean ± SD) in the patients with cGVHD (n = 14); 0.83 ± 0.40 in the patients before transplantation (n = 23); 0.74 ± 0.51 in the patients with no cGVHD development after transplantation (n = 6) and 0.82 ± 0.31 mg/ml in the control group of normal donors (n = 16 and 5 PNS). This evidence concerns the gene HP and paraneoplastic neurologic syndrome.