CA9 and astrocytoma (excluding glioblastoma): When both pcDNA3.1-ANKDD1A and pGL3-CA9 plasmids were co-transfected in HEK293T and astrocytoma cells, we found that the ectopic expression of ANKDD1A dramatically reduced the FLuc activity under hypoxic stress but only slightly decreased it under normoxia (Fig. 4c).