FKBP3 (FK506-binding protein 3) is a prolyl isomerase and immunophilin family member that functions as a protein-folding catalyst and signaling regulator 1. It contains a Basic Tilted Helix Bundle domain with DNA-binding capability and interacts with transcription factors including YY1 1. Beyond canonical immunosuppressant binding, FKBP3 plays critical roles in oncogenic signaling across multiple cancer types. In non-small cell lung cancer, FKBP3 promotes proliferation through the Sp1/HDAC2/p27 axis, with high expression correlating with poor survival 2. In diffuse large B-cell lymphoma, FKBP3 aggravates malignant phenotype and stemness via PARK7-mediated Wnt/β-catenin pathway activation, while being transcriptionally suppressed by FOXO3 3. In nasopharyngeal carcinoma, FKBP3 enhances HDAC2-dependent NF-κB/IL-6 signaling to promote cell growth and invasion 4. Additionally, FKBP3 maintains HIV-1 latency by recruiting HDAC1/2 to the viral long terminal repeat through YY1 interaction, suggesting epigenetic regulatory capacity 5. In lung adenocarcinoma, elevated FKBP3 associates with poor prognosis and suppresses anti-tumor immune infiltration while regulating ferroptosis 6. FKBP3 emerges as a promising therapeutic target across malignancies.