Using the same primer pair sets previously reported [42] (also shown in Supplementary Table S1), we measured RNAPII occupancy at PPP sites, introns and transcription end sites (TES) of these seven genes in human osteosarcoma U2OS cells that are either wild type (WT) or knockout (KO) for CSB [15,16] (Figure 1A). Here, ERCC6 is linked to osteosarcoma.