MLLT3 and leukemia: One cytokine commonly upregulated in KMT2A-MLLT3 leukemias co-expressing an activating mutation (FLT3ITD, FLT3N676K, or NRASG12D) as compared to those induced by KMT2A-MLLT3 alone, and normal healthy hematopoietic subpopulations, was the macrophage migration inhibitory factor (Mif), a lymphokine that stimulate pro-inflammatory processes (Fig. 5a and Supplementary Fig. 10b).