A and B) Diffusion modeling incorporating dephosphorylation kinetics indicates substantial truncation of the root-mean-square (r.m.s.) displacement for STAT-3 diffusion (dashed red line compared to solid red line). This has the effect of reducing the crossing point at which signaling endosome transport (solid blue line) overcomes diffusion (ca. 2 μm for theoretical r.m.s. vs. transport reduced to ca. 200 nm for adjusted r.m.s. vs. transport). B shows same data as A at higher Y-axis magnification.