We profiled four primary MLL-AF4 ALL patient samples (three males and one female), including three childhood (1–18 years old; chALL#1, chALL#2 and chALL#3) and one infant (≤1 year old; iALL#2), combining gene expression and chromatin accessibility data with TOPmentation and ChIP-seq for H3K4me1, H3K4me3, H3K27ac, H3K27me3, H3K79me2 and the N-terminus of MLL-AF4 (Supplementary Table 1). This evidence concerns the gene AFF1 and acute lymphoblastic leukemia.