Using qRT-PCR and western blotting, both mRNA and protein levels of Nanog and Oct-4 were found to be significantly upregulated following lentiviral expression of an miR-223 inhibitor and withdrawal of bFGF for 120 h, compared with withdrawal of bFGF in the absence of lentiviral infection (Fig. 2D, E). Here, POU5F1 is linked to infection.