We further determined that the accumulation of three major DC subsets and in particular the MHC IIhi CD103+ and CD11bhi DC in the MLN of infected animals was not due to recent local cell proliferation, as less than 5% of these DC subsets had undergone recent cell division as determined by the expression of the nuclear antigen Ki-67, a marker for recent cell proliferation [32] (Fig. 3C); and administration of the thymidine analog BrdU continuously during the first 3 days of infection resulted in a fraction (<30%) of CD103+ and CD11bhi DC incorporating this analog into DNA (Fig. S6A). This evidence concerns the gene MKI67 and infection.