CD47 and viral infectious disease: In contrast to the FnBP A+/B+ strain, where adherence to the viral infection-induced CD47 was inhibited by α-hCD47 antibodies in a concentration-dependent manner (Fig. 3f), the double deletion mutant strain (FnBP A–/B–) showed less adherence to viral infection-induced CD47, and this adherence was not affected by CD47 blocking (Fig. 3g).