IKZF1 and acute lymphoblastic leukemia: Although deletion of IKZF1 was not associated with higher CFZ sensitivity in 79 BCP-ALL cell lines including Ph+ALL cell lines, 11 Ph-negative BCP-ALL cell lines carrying IKZF1 deletion (1.93 nM; 3.11 ± 2.42 nM) were significantly more sensitive to CFZ than 54 Ph-negative BCP-ALL cell lines without the deletion (5.53 nM; 7.35 ± 10.8 nM; p = 0.013) (Fig 5B).