FURIN and infection: Moreover, infection of CHO-K1 wild-type cells also resulted in a more robust (approximately 30-fold) increase of infection in the presence of FPC particles, while neutralization with the HPV16-neutralizing antibody H16.V5 (but not with the HPV18-neutralizing antibody H18.J4) abolished infectious uptake independently of furin pretreatment as expected (53) in both cell types (Fig. 1C).