Immunoblotting of the membrane fractions of endosomes purified from the infected CHO-K1 cells after different periods of infection (5–120 min) revealed the simultaneous presence of ACT, Cav-1 (a major protein forming membrane caveolae), and Rab-5 (The same amount of protein was loaded in each case) (Fig. 6b). This evidence concerns the gene RAB5A and infection.