Validation of Bmi-1 target genes identified by microarray analysis. Knockdown of Bmi-1 expression in L428 cells resulted in the down-regulation of HK2, c-MET, BNIP3, and P4HA1 mRNA (left). Changes in the protein levels of HK2, c-MET, and BNIP3 were also demonstrated (right). P4HA1 could not be confirmed at the protein level because of the lack of a suitable antibody.