KLF4 and precursor B-cell acute lymphoblastic leukemia: Based on these findings and in line with our previous observation and published results that i) KLF4 is severely downregulated in primary pediatric B-ALL cells [35–38], especially after therapy [43] (Supplementary Figure S4A), and ii) among adult ALL samples, the aggressive Ph+-like B-ALL subgroup showed low expression levels of KLF4 similar to those of T-ALL [22] (Supplementary Figure S4B); we went on to investigate a putative role of KLF4 in leukemia models of advanced disease.