Nodal/Activin Signaling in ES Cell Fate Decisions Figure 6. Graded, Low Signaling Dominant, High Signaling Dominant, and Multimodal Modes of Phospho-Smad2 Target Gene Binding. UCSC Genome Browser representation of pSmad2 enrichment peaks under Activin (red), DMSO control (blue) and SB (green) signaling PLoS Genetics | www.plosgenetics.org 12 June 2011 | Volume 7 | Issue 6 | e1002130