Western blot analysis of hFIX. Lane 1, medium of myotubes carrying LIXSN; lane 2, medium of myotubes carrying pdLMe4βAhIXm1; lane 3, medium of myotubes carrying BAG; lane 4, hFIX precipitated from pooled normal human plasma; and lane 5, recombinant hFIX (100 ng). Numbers on the left indicate the molecular size markers. The hFIX band position is shown on the right. Protein bands with an approximate size of 52 kD in lanes 1 and 2 may correspond to degradation products of hFIX during the protein preparation procedure.