YJEFN3 (YjeF N-terminal domain containing 3) is a protein with proposed roles in cholesterol metabolism and hematopoietic development. Based on functional similarity to AIBP, YJEFN3 may facilitate cholesterol efflux from endothelial cells to HDL, potentially activating the transcription factor SREBF2 and promoting NOTCH signaling to regulate hematopoietic stem and progenitor cell emergence from hemogenic endothelium 1. The gene contains NAD(P)HX epimerase activity and localizes to membrane rafts and mitochondria, consistent with lipid metabolism functions. In disease contexts, YJEFN3 has emerged as a potential tumor antigen for prostate adenocarcinoma mRNA vaccine development, identified among overexpressed and mutated candidates with poor prognostic value 2. In colorectal cancer, YJEFN3 was identified as a mitochondrial lipid metabolism-related gene associated with disease prognosis and immune landscape, with functional studies showing that YJEFN3 knockdown suppressed cancer cell proliferation, migration, and invasion 3. Additionally, YJEFN3 was identified as a potential functional gene linking autoimmune hepatitis with psychiatric comorbidity through shared genetic pathways in brain tissues 4. These findings suggest YJEFN3 participates in both developmental hematopoiesis and cancer-related pathways.