Progression from F+A− to F+A+ with time in culture.

F+A− cells (defined in Figure 1) were quantitated at different culture times (days 7, 10, 13, and 16) and expressed as a percentage of all F+ cells (note: not of all Hb+ cells). Results from all individual cases are shown (open circles) to indicate range and distribution of values. Averages are shown by horizontal bars. C = control; T = TGFβ treatment. The difference in F+A− proportions between TGFβ-treated and control cultures on day 7 is significant with P < .0001.