STAT3 and diffuse large B-cell lymphoma: Furthermore, high expression of STAT3 protein in DLBCL tumors as detected by immunohistochemistry (IHC) has been associated with unfavorable outcome in some, [15] but not all studies.[16–18] In addition, previous studies have demonstrated deregulation of JAK/STAT3 signaling in DLBCL.[16, 19, 20].