Negative-selection screen using CRISPR/Cas9. (A) Schematics of the screen. Vector used to establish a clonal Cas9-expressing MLL-AF9 leukemia cell line and vector used for sgRNA transduction (upper). Experimental scheme (lower). (B) Fold changes in TdTomato positivity (day 2/day 14) during 14 days in culture. Each bar represents an sgRNA targeting Jmjd1c. The black bar represents sgRNA against Dot1l. Shaded areas are sgRNAs targeting ZFD (green) and Jumonji domain (blue). (C-F) Time course of flow cytometry analysis of TdTomato level after lentiviral transduction of sgRNAs. (B-F) Data are mean ± standard deviation of independently transduced triplicate samples.