PDCD10 and brain neoplasm: The promoter activities in the direction of PDCD10 in all cells tested were approximately 4 to 10-fold higher than those of SERPINI1. Moreover, the promoter activities toward the SERPINI1 direction were higher in brain tumor H4 and U-87 MG cells than those in other test cells, and they were nearly 3-fold higher than the positive control, the viral SV40 minimal promoter (Fig. 3).