For example, the rs12203592 intronic polymorphism in the interferon regulatory factor 4 (IRF4) gene was linked to a higher risk of acute lymphoblastic leukemia, where a C to T substitution increased IRF4 gene expression by altering the binding affinity of the activator protein 2α transcription factor (TF) 30. This evidence concerns the gene TF and acute lymphoblastic leukemia.