FAS and chronic myelogenous leukemia, BCR-ABL1 positive: Watanabe et al. demonstrated that IRF8 expression was downregulated in CML patients, and Irf8-/- mice developed a CML-like disease.569 IRF8 partially suppressed CML development in vivo through a Fas-dependent apoptosis mechanism.570 IRF8 acts as a roadblock for β-catenin-driven leukemia.