However, while all these interactions with RNAPIIo were abolished in CSB-KO cells (Fig. 8a), in line with the essential role of this protein in TCR, the UV-induced association of these TCR proteins with RNAPIIo was not affected in two independent HMGN1/HMGN2-dKO clones in either osteosarcoma (Fig. 8a, Supplementary Fig. 2A,B) or retinal epithelial cells (Fig. 8b, Supplementary Fig. 3A,B). Here, HMGN1 is linked to osteosarcoma.