CD25-dificient patient-derived PDX2 B-ALL cells and Jeko1 MCL cells with CRISPR-Cas9-mediated gene deletion were reconstituted with wild-type CD25 (S268) or CD25 carrying S268A mutant (A268) with C-terminal BirA (engineered biotin ligase) and selected by puromycin for 3 days. BirA expressing construct was used as negative control.