POU5F1 and infection: Further confirming this finding, the expression of HIF-2α-specific downstream genes (PAI1, POU5F1, SOD2, and CITED2) did not change in RCC4 or 780-O (a pVHL-deficient kidney cancer cell line containing only HIF-2α) cells after infection with the EPEC strains with or without NleB [32,33], and bacteria-delivered NleB also did not change the expression of HIF-2α-specific downstream genes (S11G and S11H Fig).