MYC and osteosarcoma: At the same time, MYC binds directly to PAF1c and activation of MYC in osteosarcoma cells recruits PAF1c to its target promoters and, via PAF1c, promotes double-strand break repair at promoters63; we show here hat endogenous MYC in pancreatic carcinoma cells is required to recruit PAF1c to RNAPII.