STAT3 and neoplasm: The inhibitory effect of blocking STAT3 signaling on the early cytokine response but not on NK cell degranulation suggests that the delivery of STAT3 inhibitors may be beneficial only after IL-15 priming has been allowed to enhance NK cells adaption to the hypoxic tumor environment, e.g., in the context of a combination of NK cell and IL-15 therapy with STAT3 inhibition.