STAT3 and B-cell non-Hodgkin lymphoma: We have recently reported that a positive feedback loop between STAT3 and HSPs also occurs in primary effusion lymphoma (PEL) cells [7], a rare B cell lymphoma associated with Kaposi sarcoma herpesvirus (KSHV) and, in most of the cases, also with Epstein–Barr virus (EBV) [8].