Clones 13 (A), 15 (C), 57 (B), 67 (F–H), and 68 (D and E) were cytospun, fixed, and stained with May-Grünwald and Giemsa. Label notation indicates the unique clone number, the phenotype, the infected or uninfected nature of the cells, and the corresponding amount of tax mRNA, measured in arbitrary units. Compared with uninfected CD8+ clones (A), HTLV-1–positive CD8+ clones (B) displayed enlarged cells with enlarged cytoplasm. Compared with uninfected CD4+ clones (C), HTLV-1–positive CD4+ clones (D and E) frequently display giant cells, some harboring enlarged nucleus (arrows). Multinucleated cells frequently displayed nuclei of heterogeneous sizes, as identified by arrowheads in E and G and shown at higher magnification in F. Chromatin bridges connecting nuclei in multinucleated cells are identified by smaller arrows in G and H. The distribution of cellular nuclearity according to phenotype and infectious status is shown in I. *P < 0.001; **P < 0.0001, infected vs. uninfected cells. Magnification, ×40 (A–E), ×100 –H).