GRP94 expression in vivo. (A) Enhanced factor VIII secretion by inactivation of GRP94. NRK-Vect and NRK-Ribo cells transfected with pMT2-factor VIII were analyzed for their ability to secrete factor VIII in the presence or absence of MMC. (B) Invariant GRP94 levels in parental and complemented FA-C cells. Lysates of parental HSC536 and HSC536-FAC cells were analyzed by immunoblotting with anti-GRP94 antibody. Each lane contained 10 μg protein as determined by the Bradford assay.