Cover photo courtesy of Chen et al, "In Vitro Studies on Cellular and Molecular Mechanisms of Arsenic Trioxide (As₂O₃) in the Treatment of Acute Promyelocytic Leukemia: As₂O₃ Induces NB₄ Cell Apoptosis With Downregulation of Bcl-2 Expression and Modulation of PML-RAR/PML Proteins."