This study aims to explore the mechanism of action of the Bromodomain-containing protein 4 (BRD4) inhibitor GNE-987 in the treatment of pediatric T-cell Acute Lymphoblastic Leukemia (T-ALL), focusing on its effect in inhibiting T-ALL cell proliferation by activating the HLA Complex P5 (HCP5) Super-enhancer. Here, HCP5 is linked to acute lymphoblastic leukemia.