Proliferation of naïve transgenic cells during latency. A, 7 d after transfer, spleens from recipient mice were harvested. Dot plots show the CFSE levels and CD44 expression on the indicated donor populations. B, 14 d after transfer, spleens and lungs were harvested and stained as in panel A. The percent of each donor population that exhibited CFSE dilution (CFSElo) is shown (n=3, representative of 2 experiments).