SCFD2 (sec1 family domain containing 2) is a putative protein transport regulator belonging to the Sec1 family of proteins. The gene is annotated for roles in intracellular protein transport and vesicle-mediated transport 1, though direct functional validation is limited in the provided literature. Clinically, SCFD2 has emerged as significant in multiple malignancies. In acute myeloid leukemia, ETV6-SCFD2 fusion events occur in t(4;12)(q12;p13) translocations and represent an alternative to previously misidentified ETV6-PDGFRA fusions, explaining imatinib insensitivity in affected patients 1. In ER-positive breast cancer, SCFD2 functions as a downstream target of the RNA-binding protein PSF/SFPQ and serves as an independent poor prognostic indicator; SCFD2 knockdown suppresses breast cancer cell proliferation and tamoxifen-resistant tumor growth 23. SCFD2 expression is post-transcriptionally regulated by both PSF and PSPC1, with elevated SCFD2 immunoreactivity correlating with poor prognosis in hormone-dependent breast cancer 3. Additionally, long noncoding RNA lnc-SCFD2-2 shows association with progression-free survival in prostate cancer, suggesting SCFD2's involvement in metastatic disease progression 4. SCFD2 was also identified as a p53 target gene under stress conditions 5. These findings position SCFD2 as a potential therapeutic target in hormone-refractory cancers and a biomarker for aggressive malignancies.