GRN and Autoimmunity: Additionally, this hyperphosphorylation prevents direct binding to and inhibition of tumor necrosis factor receptor 1 (TNFR1), TNFR2, and DR3 by PGRN and alters the conversion of progranulin into mature granulin motifs.4 Therefore, not only PGRN‐Abs restricts progranulin function but the cause for autoimmunity to progranulin itself limits progranulin function.