Total RNA was extracted as described in the RT-qPCR protocol section. Banks for deep-sequencing were prepared from 800 ng total RNA using Illumina's TruSeq Stranded mRNA LT Kit according to manufacturer's protocol. Samples were sequenced paired-end at 50-bp read length on an Illumina HiSeq-2000. As described in supplementary methods, the reads were trimmed using Trimmomatic, aligned onto the hg19 reference genome using TopHat2, filtered using SamTools, then the FPKM calculated using Cufflinks (21 –24 (link)).