L929 cells transduced to co-express mCherry and Apol9b or Apol9a, or mCherry alone (vector), were subsequently transduced with lentiviral vectors co-expressing shRNAs targeting the coding sequence of either Phb1 or Phb2 and the far-red fluorescent E2-Crimson protein [47], prior to infection with the GFP-expressing KJ7 virus. Here, PHB1 is linked to infection.