To determine the effects of ASXL1 correction in vivo, we xenografted uncorrected KBM5 cells and two homozygous ASXL1 mutation-corrected KBM5 clones into non-obese diabetic–severe combined immunodeficiency–IL-2Rγ null (NSG) mice. This evidence concerns the gene ASXL1 and severe combined immunodeficiency.