FIG. 4.

Withdrawal of FTI from inhibited H-Ras-expressing cells causes a cessation of proliferation and rapid differentiation. H-Ras-expressing cells were collected from primitive monocytic colonies formed in the presence of 50 nM FTI. The appearance of these cells after 4 days of suspension culture in the presence (A) or absence (B) of 10 nM FTI is indicated (magnification, ×100). The expression of CD33, CD15, HLA-DR, and CD14 on cells after 4 days with (C to E) or without (F to H) FTI was measured by flow cytometry.