RNA was extracted from 5*10^6 cells using RNeasy Plus Mini Kit (Qiagen) and DNA was eliminated by treatment with the RNase-Free DNase Set (Qiagen). RNA was treated with the NEBNext rRNA Depletion kit (NEB #E7405L) and strand-specific RNA libraries were prepared using the NEBNext Ultra II Directional RNA Library Prep with Beads (NEB #E7765S) NEBNext Ultra II Directional RNA Library Prep with Beads (NEB #E7765S) following the manufacturers protocol.