No significant changes were observed in the expression of HIF1α and HIF2α over time under normoxic conditions; however, culture under hypoxic conditions for 24 and 48 h, led to relatively higher levels of HIF1α and HIF2α in the NP epithelial cells compared with those in the IT (CONTROL) and IT (CRS) groups in a time-dependent manner. Here, EPAS1 is linked to congenital rubella syndrome.