Similarly large total numbers of lymphocytes, CD4+ T-lymphocytes, and CD8+ T-lymphocytes were detected in BALF after infection with WT, rSeV-luc(M-F*), or rSeV-luc(F-HN) virus (Figure 1F; Figure S3A–B), whereas mice inoculated with the attenuated rSeV-luc(P-M) had total lymphocyte counts only 10% as high. Here, CD4 is linked to infection.