Myc Binding Protein (MYCBP), also known as Partner of MYC1 (PAM1), is a critical regulator of the oncoprotein c-Myc. It modulates c-Myc transcriptional activity by stabilizing its interaction with DNA or promoting its proteasomal degradation, thereby influencing cell proliferation, apoptosis, and tumorigenesis. MYCBP is essential for maintaining genomic stability and regulating cell cycle progression. Dysregulation of MYCBP is implicated in cancers, particularly those driven by c-Myc overexpression, such as lymphoma and breast cancer. Additionally, MYCBP interacts with other transcription factors and chromatin remodelers, serving as a scaffold for multiprotein complexes that fine-tune oncogenic or tumor-suppressive signaling pathways.Furthermore ,MYCBP can promote HOXB4 degradation via ubiquitination, negatively regulating hematopoietic stem cell self-renewal to maintain differentiation balance.Thus a functional ELISA assay was conducted to detect the interaction of recombinant human MYCBP and recombinant human HOXB4.Briefly, biotin-linked HOXB4 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to MYCBP-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µl stop solution to the wells and read at 450/630nm immediately. Measured by its binding ability in a functional ELISA. When Recombinant MYCBP is lmmobilized at 2 ug/mL(100 uLwell), the concentration of HOXB4 that produces 50% optimal bindingresponse is found to be approximately 0.21ug/mL.