B, HCT116 cells were treated for 2 hrs with 100 nM Thapsigargin in the presence or absence of shRNA targeting USP22. Cells were cross-linked, harvested, and subjected to ChIP-qPCR for total RNA Pol II, pSer5 Pol II, and pSer2 Pol II at the loci across CHOP (indicated in A). Three independent experiments are represented as mean ± SEM 