SUMF2 (sulfatase modifying factor 2) is a regulatory protein that lacks formylglycine generating activity and functions primarily as an inhibitor of sulfatase activation. Unlike its paralog SUMF1, SUMF2 cannot convert inactive sulfatases to their active forms and instead inhibits sulfatase activation by forming heterodimers with SUMF1 in the endoplasmic reticulum 1. SUMF2 demonstrates additional regulatory functions beyond sulfatase modulation, notably through direct interaction with interleukin-13 (IL-13), a key mediator of allergic inflammation. This interaction occurs independently of IL-13 glycosylation and results in inhibition of IL-13 secretion from bronchial smooth muscle cells and lymphocytes 2. Multiple SUMF2 subtypes can interact with both wild-type and mutated IL-13, suggesting diverse regulatory mechanisms 3. In disease contexts, SUMF2 shows clinical relevance as a potential biomarker. Hypermethylation of specific SUMF2 CpG sites correlates with shorter progression-free and overall survival in colorectal cancer patients 4, and SUMF2 is identified as a shared diagnostic marker for type 2 diabetes mellitus and chr7 obstructive pulmonary disease 5. These findings indicate SUMF2's role extends beyond sulfatase regulation to encompass immune modulation and disease pathogenesis.