To determine whether this increase was simply a consequence of providing more Oct-1, we performed parallel infections with a human Oct-1 derivative in which the two non-conserved residues on helix-2 (corresponding to POUH sequence glutamic acid-30 and methonine-33, highlighted in Figure 5A) were swapped to the rodent equivalent (aspartic acid-30 and leucine-33). Here, POU2F1 is linked to infection.