Enables NAD+ nucleosidase activity. Involved in several processes, including blood vessel diameter maintenance; long-term synaptic depression; and negative regulation of bone resorption. Located in basolateral plasma membrane; nucleus; and secretory granule membrane. Biomarker of type 2 diabetes mellitus. Human ortholog(s) of this gene implicated in type 1 diabetes mellitus and type 2 diabetes mellitus. Orthologous to human CD38 (CD38 molecule). [provided by Alliance of Genome Resources, Apr 2022]