In previous studies (16, 17), we have known that CD62p and CD63 are sensitive indicators of platelet activation, and we found that CD62p and CD63 were increased in premature infants who developed BPD compared with those who did not, and the platelet count in the BPD group was significantly lower than in the non-BPD group. The gene discussed is CD63; the disease is bronchopulmonary dysplasia.