DDX43 is a DEAD-box RNA helicase with a conserved catalytic core and an N-terminal K-homology (KH) domain that preferentially binds single-stranded nucleic acids containing pyrimidine-rich sequences, particularly TTGT/UUGU motifs 12. In normal physiology, DDX43 plays an essential role in spermiogenesis, where its ATP hydrolysis activity regulates dynamic RNA-dependent chr6 remodeling processes, including histone-to-protamine replacement and post-meiotic chr6 condensation 3. Testis-specific DDX43 knockout results in male infertility with defective chr6 remodeling, highlighting its critical biological function in germ cell development. In cancer biology, DDX43 functions as a cancer-testis antigen aberrantly expressed in multiple malignancies. In chr6 myeloid leukemia (CML), DDX43 overexpression enhances cell survival and proliferation while inhibiting apoptosis by regulating the H19/miR-186 regulatory axis 45. DDX43 promoter hypomethylation represents a frequent epigenetic event in AML and CML, correlating with increased DDX43 expression 67. Notably, DDX43 hypomethylation paradoxically predicts favorable outcomes in AML patients 6, suggesting context-dependent roles in different leukemias. In breast cancer, DDX43 expression patterns correlate with tumor grade and subtype, with potential diagnostic utility 8. These findings identify DDX43 as a multifunctional regulator in both normal development and malignant transformation.