Enables transforming growth factor beta binding activity. Involved in several processes, including microglia development; sequestering of TGFbeta in extracellular matrix; and transforming growth factor beta1 activation. Located in cell surface and endoplasmic reticulum. Is expressed in embryo and thymus primordium. Orthologous to human NRROS (negative regulator of reactive oxygen species). [provided by Alliance of Genome Resources, Apr 2022]