Background: In children, acute lymphoblastic leukemia (ALL) serves as the 
most prevalent blood malignancy. Based on the American Cancer Society, there 
were 1580 fatalities and 5690 reported as new cases of ALL in adults and 
children in the United States (US) in 2021. 
Aim of the Work: The objective of this research is to examine the expression 
levels of the FoxO3a gene in bone marrow samples of pediatric patients with 
ALL using real-time polymerase chain reaction (PCR), in order to develop a 
newly targeted treatment for the disease and determine whether there is a 
relationship between the expression levels of FoxO3a gene, the clinical 
presentation and laboratory data of these patients.
Subjects and Methods: This research was performed on fifty-three recently
diagnosed pediatric ALL cases, according to the 2016 World Health 
Organization (WHO) categorization (36 were B-acute lymphoblastic leukemia 
(B-ALL) versus 17were T-acute lymphoblastic leukemia (T-ALL)) and 30 
healthy participants age and sex matched to cases as a control group. These 
individuals were admitted at the South Egypt Cancer Institute (SECI), Assiut 
University in the period from June 2020 to December 2021. 
Results: FoxO3a gene was significantly downregulated in ALL patients. 
Statistically significant correlations among downregulation of FoxO3a gene, 
hepatosplenomegaly, and the higher percentage of peripheral (P.B) blast cells 
were recorded. 
Conclusion: FoxO3a gene acts as tumor suppressor gene, thus rendering 
FoxO3a gene as potential target for treating ALL as one of hematopoietic 
malignancies.