MAPK3 and chronic myelogenous leukemia, BCR-ABL1 positive: To further determine the effects of Prmt1 loss on the self‐renewal of LSCs, we sorted GFP+c‐Kit+ cells from the primary Prmt1fl/fl; Cre‐ERT2 or Prmt1fl/fl CML mice and performed in vitro CFC/replating assay or in vivo disease reconstitution assay (Figure S4E, Supporting Information).