FER1L6 is a calcium/phospholipid-binding protein belonging to the ferlin family, which includes six members in humans that share common features such as multiple Ca2+-binding C2 domains and roles in calcium-triggered membrane fusion and vesicle trafficking 1. The protein shows concentrated localization to the trans-Golgi network and recycling endosomes, cycling rapidly between these compartments and the plasma membrane via Rab11 recycling endosomes, distinguishing it from other ferlins that localize to plasma membrane/late endosomes 2. Structural analysis reveals FER1L6 contains remarkably consistent domain ranges with other ferlins, including a previously unknown C2-FerA domain 3. FER1L6 demonstrates tissue-specific expression patterns and has been implicated in diverse biological processes. The gene shows gastric-type expression in invasive mucinous adenocarcinoma of the lung, with >15-fold increased expression compared to typical lung adenocarcinomas 4. Additionally, FER1L6 variants have been associated with longevity in European bison, showing possible sex-dependent effects 5, and a novel missense mutation has been identified in familial multiple supernumerary teeth 6. The gene also appears relevant in cancer contexts, with altered expression patterns observed in various malignancies 78.