These results from replication kinetics over a 7-day period of infection lend support to the observation that the presence of R263K or H51Y/R263K in the IN sequence together with K65R, L74V, K103N, E138K, or M184V/I in the same virus resulted in slight to significant decreases in viral replication capacity (Fig. 1a–f). Here, CD44 is linked to infection.