Deletion of GADD45A promotes engraftment of human AML PDX cells in NSG mice. (A) Schematic describing in vivo generation of CRISPR/Cas9-mediated knockout (KO) of GADD45A in PDX mice. Also see supplemental Figure 4 for the additional experimental detail. (B) Representative in vivo bioluminescence imaging and total flux (photons/second [p/s]) of GADD45A KO PDX mice (n = 9) vs CRISPR control (Ctr) PDX mice (n = 6) in primary NSG recipients. A total of 5 × 10⁴ mCherry⁺ GFP⁺ PDX cells were transplanted into each of recipient mice. Scatter dot plots represent the mean ± SD. ∗∗∗P < .0005, ∗∗∗∗P < .0001, 2-way ANOVA. (C) Representative in vivo bioluminescence imaging and total flux (p/s) of GADD45A KO PDX mice (n = 5) vs CRISPR Ctr PDX mice (n = 6) in secondary NSG recipients. A total of 1 × 10⁵ mCherry⁺ PDX cells from primary recipient mice were transplanted into each of secondary recipient mice. Data are given as mean ± SD. ∗∗P < .005, ∗∗∗P < .0005, ∗∗∗∗P < .0001, 2-way ANOVA. (D) Quantitative polymerase chain reaction (qPCR) confirming stable knockout of GADD45A and showing relative expression levels of WNT/self-renewal target genes in GADD45A KO vs CRISPR Ctr hCD33⁺ PDX bone marrow (BM) cells (n = 3). Data are given as mean ± SEM. ∗P < .05, ∗∗P < .005, unpaired t-test.