PITPNB (phosphatidylinositol transfer protein beta) is a lipid transfer protein that catalyzes the bidirectional transfer of phosphatidylinositol and phosphatidylcholine between cellular membranes 1. It plays a critical role in COPI-mediated retrograde transport from the Golgi apparatus to the endoplasmic reticulum, with both phosphatidylinositol and phosphatidylcholine transfer activities essential for this function 2. PITPNB regulates phosphatidylinositol-4-phosphate (PI4P) metabolism at the Golgi, and its dysregulation activates mammalian Golgi stress responses that can trigger transcriptional changes and cell death 3. Beyond its canonical transport function, PITPNB has emerged as a disease-associated gene in multiple contexts: it was identified as a hub gene in moyamoya disease pathogenesis 4, appears in brain proteomic signatures associated with Alzheimer's disease progression 5, and is a shared genetic risk factor between breast cancer and intracranial meningioma 6. PITPNB deletion has been associated with craniofacial abnormalities including cleft palate 7. These findings suggest PITPNB functions extend beyond vesicular transport to encompassing roles in stress signaling, vascular disease, neurodegeneration, and cancer pathogenesis.