Specific tyrosine residues of PDGFR are selectively phosphorylated on lipid raft platforms as a function of cell confluence

Activation of the Ras-MAPK pathway and consequential cell proliferation is dominant in sparse cultures

Activation of the Akt survival kinase shows similar patterns in sparse and confluent cultures

Activation of the PLCγ pathway, de-activation of the Ras-MAPK pathway, and cell migration dominates in confluent cultures

The same stimulus promotes distinct outputs relevant to the tumor’s actual requirement for proliferation vs. spreading