Figure 3.

A time-course experiment showing the natural differentiation or transition of CD14⁺ monocytes into CD14⁺CD16⁺ cells (pink arrow at 24 h) in citrated whole blood even in the absence of any stimulus. Note that CX₃CR1 expression levels on all monocyte subsets decrease over time, whereas CCR2 is expressed only on CD14⁺ and at a low level on CD14⁺CD16⁺ monocytes but is also downregulated with time. FSC, forward scatter channel. SSC, side scatter channel. ‘-’, negative expression. ‘+’, low-to-intermediate level of expression. ‘++’, high level of expression.