SLC35F5 is a solute carrier family member with primary function as a choline transporter 1. The protein demonstrates significant organic cation transport activity, with particular emphasis on choline uptake 1. Mechanistically, computational modeling and gene ontology analysis suggest SLC35F5 likely localizes to the Golgi apparatus and functions as an importer of flavin adenine dinucleotide (FAD), with predicted substrate affinity of 0.1-0.4 nM 2. This FAD import function is proposed to support disulfide-bond formation during post-translational modification of secretory proteins 2. SLC35F5 displays ubiquitous mRNA expression across adult and fetal tissues 3, suggesting broad physiological relevance. Clinically, SLC35F5 has been implicated in chemoresistance, where miR-369-3p-mediated downregulation of SLC35F5 sensitizes non-small cell lung cancer cells to cisplatin through disruption of nucleotide sugar transportation 4. Additionally, SLC35F5 expression levels predict 5-fluorouracil chemosensitivity in colorectal cancer, where it functions as part of a three-gene response index for predicting chemotherapy efficacy 5. SLC35F5 has been identified as a candidate disease gene in Mendelian disorders affecting neurocognitive development 6.