DTX1 (deltex E3 ubiquitin ligase 1) functions as a regulator of the Notch signaling pathway, a critical cell-cell communication system involved in cell fate determination 1. As an E3 ubiquitin ligase, DTX1 mediates protein ubiquitination, though unlike DTX3L, it lacks the ability to directly ubiquitylate nucleic acids 2. The protein plays important roles in lymphatic development, where it participates in a mechanotransduction pathway involving Piezo1 and Orai1 that regulates flow-activated lymphatic expansion through Notch downregulation 3. DTX1 is located on chromosome 12 within the Noonan syndrome critical region, though its role in this disorder remains unclear 4. In cancer contexts, DTX1 appears to function as a tumor suppressor, particularly in head and neck squamous cell carcinoma (HNSCC), where it is downregulated by promoter hypermethylation 1. Loss of DTX1 expression may contribute to increased cell migration and tumor progression. Additionally, DTX1 is involved in genetic subtyping of diffuse large B-cell lymphoma as part of the BN2-like subtype 5. The protein also influences regulatory T cell function by affecting FOXP3 stability 6.