IL2 and cancer: In previous studies we demonstrated that circulating Hsp70 levels, which were quantified with the compHsp70 ELISA [31], act as danger-associated molecular patterns (DAMPs) which, in combination with pro-inflammatory cytokines such as IL-2, are able to stimulate membrane Hsp70-specific, NK cell-mediated anti-cancer immune responses in vitro and in vivo, as demonstrated in a clinical phase II trial with NSCLC patients [26,33,34].