SPRY4 and infection: Ectopic expression was achieved by infection with the respective recombinant adenoviruses, and migration of the cells in a scratch assay revealed that, compared to the control cells, the presence of each of the two Spry4 forms inhibited closure of the produced gap within 20 h, a period of time that was sufficient for the control CRL2868 cells to restore the lawn (Figure 5A).