Also in a multivariate regression analysis between dyshemoglobins which were carboxyhemoglobin as well as methemoglobin and the risk for hospitalizations ≧ 1/year, the results showed that only carboxyhemoglobin was positively correlated with the development of hospitalizations ≧ 1/year especially in COPD-PH-anemia group (Table 3). The gene discussed is HBG2; the disease is anemia.