Enables NADPH-hemoprotein reductase activity; flavin adenine dinucleotide binding activity; and heme binding activity. Involved in NADP metabolic process. Predicted to be located in perinuclear region of cytoplasm. Predicted to be active in endoplasmic reticulum. Human ortholog(s) of this gene implicated in type 2 diabetes mellitus. Orthologous to human CYB5R4 (cytochrome b5 reductase 4). [provided by Alliance of Genome Resources, Apr 2022]