containing 2-mercaptoethanol and RNA isolated using the RNeay micro kit
(Qiagen) per manufacturer’s instructions. Gene expression profiling
was performed using microarray analysis in collaboration with the Genome
Technology Access Core at Washington University. RNA was amplified using the
WTA (Sigma) system and hybridized to Agilent 8×60 gene chips. Data
analysis was performed using Partek genome suite software.