However, it is important to recognize two caveats with this experiment: 1) the narrowing of the MX2 inhibitory phenotype in HeLa cells silenced for NUP358, NUP153 or TNPO3 is largely driven by reduced infection of control cells rather than the restoration of infection in cells harboring MX2 (i.e., in contrast to what we describe in U87-MG cells, S1 Fig and Fig 2), and 2) the silencing of certain nucleoporins can result in the reduced expression of nucleoporins additional to the intended target (S3 Fig), thus making it impractical to ascribe activity to single proteins in some cases. This evidence concerns the gene NUP153 and infection.