Short RNA-seq sequencing libraries were prepared as 24-plex using the TruSeq Small RNA Sample Prep Kit (Illumina) following the manufacturer's manual. All starting sources were 1 μg of total RNA. The prepared sequencing libraries were loaded on a HiSeq2000 (Illumina). All samples profiled in this study were also profiled in the FANTOM5 promoterome paper6 and are described in detail there. Briefly, all human samples used in the project were either exempted material (available in public collections or commercially available), or provided under informed consent. All non-exempt material is covered under RIKEN Yokohama Ethics applications (H17-34 and H21-14). For the samples profiled by sRNA-seq, the human fetal heart RNA was purchased from Clontech (Cat no.636583). CD19+ B-cells and CD8+ T-cells were isolated using the pluriBead®system (huCD4/CD8 cascade and huCD19 single; PluriSelect). RNA was then extracted using the miRNeasy kit (Qiagen).
