Detection of FasL mRNA by RT-PCR in human ECFCs. Day-5 cells from three donors were cultured in control (C) medium or with 1,000 U/mL rhIFNγ (γ) for 3 days and total RNA was prepared followed by RT-PCR for FasL. The PCR product corresponding to FasL (346 bp) was purified after electrophoresis and verified by sequencing (marker, ◊x174 DNA-Hae III digest).