Binding of ¹²⁵I-SCF to HUVEC exposed for 4 hours to IL-1α (A). 2 × 10⁶ cells were incubated with varying concentrations of ¹²⁵I-SCF with and without 100-fold excess of cold SCF at 4°C. Scatchard analysis of c-kit receptors on HUVEC exposed for 4 hours to IL-1α (B). A representative experiment out of three is presented; each experiment used a single batch of HUVEC.