I) Cell viability measurements after solid phase transfection targeting POLR2A in a panel of cell lines. Cas9 expressing cell lines were transfected with scrambled and POLR2A targeting gRNA and cell viability was assessed after 5 days. The raw values are background subtracted and normalized to the mock controls. Results are from at least 3 independent experiments containing 3 technical replicates. For all cell lines, P values (scrambled vs POLR2A) < 0.005. 