It is also worth noting that cellular activities may be modulated by many factors, e.g., affinity, cellular permeability, metabolic stability, etc. However, cancer therapeutic targets have been recently prioritized using genome-scale CRISPR–Cas9 screens in 324 human cancer cell lines, which revealed that knockout of the AF9 or ENL gene suppressed the proliferation of nine or one cancer cell lines, respectively [29]. The gene discussed is MLLT3; the disease is cancer.