Similar to acute GVHD, corticosteroids have traditionally been the recommended first-line treatment for chronic GVHD.23,36 Although there is no consensus treatment for SR chronic GVHD, commonly used agents include calcineurin inhibitors, extracorporeal photopheresis (ECP), mammalian target of rapamycin (mTOR) inhibitors, rituximab, and mycophenolate mofetil. Here, MTOR is linked to chronic graft versus host disease.